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PubMed2004

Natural hybridization between a deciduous (Nothofagus antarctica, Nothofagaceae) and an evergreen (N. dombeyi) forest tree species: evidence from morphological and isoenzymatic traits.

BACKGROUND AND AIMS: Trees with a partial leaf-shedding pattern and other morphological features a priori considered intermediate between those of the deciduous Nothofagus antarctica (G. Forster) Oersted and the evergreen N. dombeyi (Mirb.) Oersted (Nothofagaceae) were found in natural stands. The hybridization between a deciduous and an evergreen species of Nothofagus has not been reported so far in natural communities. METHODS: The putative hybrids and the two presumed parental species were compared using 14 enzyme systems as well as shoot, leaf and reproductive morphology. KEY RESULTS: Six enzyme systems showed good resolution (MDH-B, IDH, SKDH, 6-PGDH, GOT and PGI) and in four of them (PGI, MDH-B, SKDH and 6-PGDH) the putative hybrids showed intermediate zymogram patterns between N. antarctica and N. dombeyi. Both principal coordinates analysis on isozyme data and principal components analysis (PCA) on quantitative morphological traits of shoots and leaves separated both parental species and located the putative hybrids closer to N. antarctica than to N. dombeyi. In the PCA, the number of basal cataphylls and the length : width ratio of leaves were the variables most discriminating among shoots of the three entities. The putative hybrids were intermediate between both species regarding leaf vernation, outline and venation, variation in leaf shape (length/width) with position on the parent shoot and in staminate inflorescence and cupule morphology. For other morphological traits, the putative hybrids resembled one of the parental species or differed from both species (e.g. valve morphology). CONCLUSIONS: Isoenzymatic and morphological data sets support the idea of the hybrid nature (probably F1 generation) of the semi-deciduous trees found. Nothofagus antarctica and N. dombeyi are probably more closely related than previously assumed. The relevance of pollen type in revealing evolutionary relationships between Nothofagus species is supported, and that of leaf-shedding pattern is rejected.

Crosses, Genetic↗
PubMed2004

The intermediate filament architecture as determined by X-ray diffraction modeling of hard alpha-keratin.

Despite investigation since the 1950s, the molecular architecture of intermediate filaments has not yet been fully elucidated. Reliable information about the longitudinal organization of the molecules within the filaments and about the lateral interfilament packing is now available, which is not the case for the transverse architecture. Interesting results were recently obtained from in vitro microscopy observations and cross-linking of keratin, desmin, and vimentin analyses. The structural features that emerge from these analyses could not be fully representative of the in vivo architecture because intermediate filaments are subject to polymorphism. To bring new light to the transverse intermediate filament architecture, we have analyzed the x-ray scattering equatorial profile of human hair. Its comparison with simulated profiles from atomic models of a real sequence has allowed results to be obtained that are representative of hard alpha-keratin intermediate filaments under in vivo conditions. In short, the alpha-helical coiled coils, which are characteristic of the central rod of intermediate filament dimers, are straight and not supercoiled into oligomers; the radial density across the intermediate filament section is fairly uniform; the coiled coils are probably assembled into tetrameric oligomers, and finally the oligomer positions and orientations are not regularly ordered. These features are discussed in terms of filament self-assembling and structural variability.

Animals↗
PubMed2001

The hormetic zone: an ecological and evolutionary perspective based upon habitat characteristics and fitness selection.

Fitness varies nonlinearly with environmental variables such as temperature, water availability, and nutrition, with maximum fitness at intermediate levels between more stressful extremes. For environmental agents that are highly toxic at exposures that substantially exceed background levels, fitness is maximized at concentrations near zero--a phenomenon often referred to as hormesis. Two main components are suggested: (1) background hormesis, which derives from the direct adaptation of organisms to their habitats; and (2) stress-derived hormonesis, which derives from metabolic reserves that are maintained as an adaptation to environmental stresses through evolutionary time. These reserves provide protection from lesser correlated stresses. This article discusses illustrative examples, including ethanol and ionizing radiation, aimed at placing hormesis into an ecological and evolutionary context. A unifying approach comes from fitness-stress continua that underlie responses to abiotic variables, whereby selection for maximum metabolic efficiency and hence fitness in adaptation to habitats in nature underlies hormetic zones. Within this reductionist model, more specific metabolic mechanisms to explain hormesis are beginning to emerge, depending upon the agent and the taxon in question. Some limited research possibilities based upon this evolutionary perspective are indicated.

Adaptation, Physiological↗
PubMed1990

Expression of the Heat Shock Response in a Tomato Interspecific Hybrid Is Not Intermediate between the Two Parental Responses.

While it is apparent that the heat shock response is ubiquitous, variabilities in the nature of the heat shock response between closely related species have not been well characterized. The heat shock response of three genotypes of tomato, Lycopersicon esculentum, Lycopersicon pennellii, and the interspecific sexual hybrid was characterized. The two parental genotypes differed in the nature of the heat shock proteins synthesized; the speciesspecific heat shock proteins were identified following in vivo labeling of leaf tissue with [(35)S]methionine and cysteine. The duration of, and recovery from, heat shock varied between the two species: L. esculentum tissue recovered more rapidly and protein synthesis persisted longer during a heat shock than in the wild species, L. pennellii. Both species induced heat shock protein synthesis at 35 degrees C and synthesis was maximal at 37 degrees C. The response of the F1 to heat shock was intermediate to the parental responses for duration of, and recovery from, heat shock. In other aspects, the response of the F1 to heat shock was not intermediate to the parental responses: the F1 induced only half of the L. esculentum specific heat shock proteins, and all of the L. pennellii specific heat shock proteins. A discussion of the inheritance of the regulation of the heat shock response is presented.

Journal Article↗
PubMed2004

Progression of liver fibrosis in blood donors infected with hepatitis C virus.

BACKGROUND/AIMS: Chronic hepatitis by HCV is progressive towards cirrhosis, with variable rate. We evaluated the rate of fibrosis progression (RFP), risk factors associated with advanced fibrosis (F3 and F4), and estimated the evolution time to cirrhosis. METHODS: We transversely selected 142 blood donors infected only with HCV, with a known route of infection, submitted to liver biopsy at admission. RFP= ratio between stage of fibrosis (METAVIR)/estimated duration of infection in years. Non-parametric tests and logistic regression analysis, with significance level of 5% were used. RESULTS: Median RFP was 0.086 U/year (0.05-0.142). Ten patients had F4 and 25 had F3. Median RFP values were significantly different (p=0.001) from one age group at contamination to the others and ALT and AST levels. There were no differences in the expected evolution to cirrhosis between intermediate fibrosers (F2) and the rapid fibrosers (F3 and F4). The independent variables associated with advanced fibrosis were ALT (OR 7.2) and GGT (OR 6.4) and age at inclusion (OR 1.12). CONCLUSION: This study suggests that RFP is extremely variable, it is exponential with age, and mainly influenced by host characteristics, especially age at contamination and possibly ethnical group. These asymptomatic patients had high percentage of fibrosis F2, F3 and F4.

Adult↗
PubMed1990

Perioperative myocardial infarction after coronary artery bypass surgery. Clinical significance and approach to risk stratification.

The clinical significance of perioperative myocardial infarction (MI) after coronary artery bypass surgery is not known. Therefore, strategies for the risk stratification of these patients do not exist. This study was undertaken to define the effect of perioperative MI on prognosis after discharge from the hospital and to develop an approach to the risk stratification of these patients. Fifty-nine patients with and 115 patients without perioperative MI were observed for 30 months for the development of cardiac events (death, nonfatal MI, and admission to hospital for unstable angina or congestive heart failure). Patients with perioperative MI were significantly more likely than patients without to have a cardiac event (31% versus 12%, p less than 0.01) and multiple events (19% versus 1%, p less than 0.001). Cox regression analysis identified two independent predictors of cardiac events other than perioperative MI (relative risk, 2.7): inadequate revascularization (relative risk, 3.5) and depressed (less than 40%) postoperative ejection fraction (EF) (relative risk, 2.1). Event-free survival rate of patients with perioperative MI varied markedly depending on the number of other negative prognostic variables present. Patients with perioperative MI who were adequately revascularized and had a postoperative EF greater than 40% had an event-free survival rate similar to patients without a perioperative MI (92% versus 87%, p = NS). Patients with perioperative MI who were inadequately revascularized and had depressed postoperative EF had an event-free survival rate of 13% (p less than 0.001 versus all other subsets). Event-free survival rate was intermediate (68%) in patients with perioperative MI and with only one of the other two variables (p less than 0.001 versus other subsets). In conclusion, perioperative MI adversely affects prognosis. Patients can be stratified into low, high, and intermediate risk subsets based on a simple assessment of the adequacy of revascularization and a determination of residual left ventricular function.

Coronary Artery Bypass↗
PubMed2006

Evaluation of a Dallas Pain Questionnaire classification in relation to outcome in lumbar spinal fusion.

Several studies have suggested that psychosocial distress is an important predictor of negative outcome in lumbar spine surgery. Ozguler et al. [Spine 27:1783-1789, 2002, 18] described a classification tool for low back pain patients using the Dallas Pain Questionnaire (DPQ) which included a measure of distress. We wanted to evaluate the ability of this classification tool to predict the outcome in spinal fusion patients. Five hundred and sixty-six patients (239 men, 327 women; mean age 46, range 18-81) operated between 1992 and 2002, with a complete DPQ preoperatively and after a minimum of 1-year follow-up, were included. They were classified preoperatively and at follow-up into four groups: group 1 (slight disability), group 2 (intermediate disability), group 3 (major disability) and group 4 (major disability and emotional distress). Using logistic regression, seven predictor variables were investigated: age (-39 years/40-59 years/60+ years), Gender (male/female), Indication (spondylolisthesis/primary degeneration/secondary degeneration), Work status (working/without work or on sick leave/retired or pensioned), Duration of pain (less than 1 year/1-2 years/more than 2 years), Presence of radiating pain (yes/no) and disability/distress [intermediate disability (group 1-2)/major disability (group 3)/major disability and distress (group 4)]. The outcome variable was disability at follow-up (low = group1 + 2/high = group 3 + 4). Preoperative classification was group 1, 1%; group 2, 14%; group 3, 37%; group 4, 48%. Variables found to predict high disability at follow-up were secondary degeneration Odds Ratio (OR) 1.61 (P=0.020), being retired/pensioned OR 3.48 (P<0.0005), age between 40-59 years OR 1.68 (P=0.011), belonging to group 3 OR 2.69 (P=0.003) or belonging to group 4 OR 5.53 (P<0.0005). The classification based on the DPQ were able to identify lumbar spinal fusion patients with a considerable amount of psychological distress in their symptomatology. Furthermore, the presence of distress, as determined by this classification, was a highly significant risk factor for inferior outcome.

Adolescent↗
PubMed2001

Glucosylceramide synthase inhibition enhances vincristine-induced cytotoxicity.

As a strategy to enhance tumor cell sensitivity to vincristine, we tested whether modulation of sphingolipid metabolism would alter vincristine cytotoxicity since this is linked to accumulation of the intermediate metabolite, ceramide. We blocked ceramide metabolism in a series of variably vincristine-resistant cell lines derived from CCRF-CEM leukemia cells using an inhibitor of glucosylceramide synthase, DL-threo-phenyl-2-hexadecanoylamino-3-pyrrolidino-1-propanol (PPPP). PPPP alone (1.0 microM), while nearly completely blocking glucosylceramide synthesis, was not toxic and did not increase cellular ceramide levels. Vincristine alone was toxic, caused apoptosis or programmed cell death (PCD) and caused an elevation in ceramide levels. Strikingly, the combination of PPPP and vincristine resulted in a further increase, over that of vincristine alone, of (i) cellular ceramide concentration, (ii) cytotoxicity associated with PCD and (iii) G2/M cell-cycle arrest. PPPP had no effect on P-glycoprotein expression or function. We conclude that vincristine cytotoxicity occurs in part through a ceramide-dependent mechanism, resulting in both G2/M block as well as PCD, and that the blockade of glucosylceramide synthase, in itself not toxic, causes augmented accumulation of ceramide resulting from vincristine exposure, which in turn maximizes ceramide-dependent, vincristine-induced cytotoxicity. Inhibition of glucosylceramide synthesis may be a means of circumventing drug resistance by enhancing signaling through a cell-death pathway.

ATP Binding Cassette Transporter, Subfamily B, Mem↗
PubMed2003

A modelling strategy for the analysis of clinical trials with partly missing longitudinal data.

Standard statistical analyses of randomized controlled trials with partially missing outcome data often exclude valuable information from individuals with incomplete follow-up. This may lead to biased estimates of the intervention effect and loss of precision. We consider a randomized trial with a repeatedly measured outcome, in which the value of the outcome on the final occasion is of primary interest. We propose a modelling strategy in which the model is successively extended to include baseline values of the outcome, then intermediate values of the outcome, and finally values of other outcome variables. Likelihood-based estimation of random effects models is used, allowing the incorporation of data from individuals with some missing outcomes. Each estimated intervention effect is free of non-response bias under a different missing-at-random assumption. These assumptions become more plausible as the more complex models are fitted, so we propose using the trend in estimated intervention effects to assess the nature of any non-response bias. The methods are applied to data from a trial comparing intensive case management with standard case management for severely psychotic patients. All models give similar estimates of the intervention effect and we conclude that non-response bias is likely to be small.

Humans↗
PubMed2005

Denaturant sensitive regions in creatine kinase identified by hydrogen/deuterium exchange.

The GdmHCl-induced unfolding of creatine kinase (CK) has been studied by hydrogen/deuterium (H/D) exchange combined with mass spectrometry. MM-CK unfolded for various periods in different denaturant concentrations was pulsed-labeled with deuterium to identify different conformational intermediate states. For all denaturation times or GdmHCl concentrations, we observed variable proportions of only two species. The low-mass envelope of isotope peaks corresponds to a species that has gained about 10 deuteriums more than native CK, and the high-mass envelope to a completely deuterated species. To localize precisely the unfolded regions in the states highly populated during denaturation, the protein was digested with two proteases (pepsin and type XIII protease) after H/D exchange and rapid quenching of the reaction. The two sets of fragments obtained were analyzed by liquid chromatography coupled to mass spectrometry to determine the deuterium level in each fragment. Bimodal distributions of deuterium were found for most peptides, indicating that these regions were either folded or unfolded. This behavior is consistent with cooperative, localized unfolding. However, we observed a monomodal distribution of deuterium in two regions (1-12 and 162-186). We conclude that the increment of mass observed in the low-mass species of the intact protein (+10 Da) has its origin in these two segments. These regions, which are very sensitive to low GdmHCl concentrations, are involved in the monomer-monomer interface of CK and their perturbation is likely to weaken the dimeric structure. At higher denaturant concentration, this would induce dissociation of the dimer.

Amino Acid Sequence↗
PubMed1999

Structure of the d(CGCCCGCGGGCG) dodecamer: a kinked A-DNA molecule showing some B-DNA features.

We have determined the structure of the dodecamer duplex d(CGCCCGCGGGCG)2. A careful use of the molecular replacement programme AMoRe has been essential in order to solve the structure. This dodecamer shows a unique conformation, quite different from all the previously studied oligonucleotide duplexes: the central octamer has an A conformation, but with a sharp 65 degrees kink in the centre; the terminal base-steps have a B-like conformation; the major groove is completely closed in the centre, a hollow molecule is thus found. The results obtained confirm the high degree of variability of DNA structure. A new type of kink and an intermediate A/B double-helical conformation have been found. Such intermediate conformation differs from those described in DNA polymerase complexes.

Base Pairing↗
PubMed1988

Coexpression of cytokeratins and vimentin in common epithelial tumours of the ovary: an immunocytochemical study of eighty-three cases.

An immunocytochemical investigation has been performed on 83 common epithelial tumours of the ovary, to ascertain their capability of expressing vimentin in addition to cytokeratins. Our results demonstrate that vimentin coexpression is related to the tumour histotype and -to a lesser extent- to the degree of differentiation of malignant variants. Indeed, most serous tumours (80%), some endometrioid adenocarcinomas, and all the clear cell carcinomas investigated exhibited a variable number of neoplastic cells co-synthesizing the two distinct intermediate filament (IF) proteins, whereas only one of 29 mucinous tumours and none of the Brenner tumours displayed vimentin-immunoreactive cells. Moreover, in serous and endometrioid carcinomas, the expression of vimentin was related to the degree of tumour differentiation, being consistently identifiable in the better differentiated cases. The immunocytochemical findings of a parallel investigation on IF expression in the ovarian coelomic epithelium and in the müllerian-derived epithelia of the female genital tract allowed us to ascertain that ovarian epithelial tumours (with the possible exception of poorly differentiated carcinomas) maintain the pattern of IF expression typical of the normal epithelia. This investigation emphasizes the usefulness of IF typing as a tool for the more precise characterization of the origin and differentiation of human neoplasms.

Adenocarcinoma↗
PubMed1983

Influence of exogenous glucagon on gastric acid secretion, mucosal blood flow, and stress ulcers in the rat: dose-response results under non-stress conditions and immobilization stress.

In non-stressed rats and rats stressed by immobilization, gastric secretion (acid, pepsin), mucosal blood flow (MBF), stress ulcers as well as glucose, insulin, and glucagon in blood were studied during 8 h, with and without additional infusion of exogenous glucagon (0.2, 1.4, 9.8 micrograms/kg/h). Metabolic clearance of glucagon and the disappearance half-time of exogenous glucagon from blood do not differ during zero stress and stress, a fact that favors the assumption of hypersecretion of glucagon as the cause of stress hyperglucagonemia. During stress alone acid secretion (volume, acidity) and MBF are lower than during zero stress; pepsin remains unchanged. Under zero stress condition additionally administered glucagon inhibits pepsin and MBF, but not acid secretion, in a dose-dependent manner. The ulcer index increased without changing the severity of ulcers. During stress the intermediate and highest glucagon doses stimulate MBF and pepsin secretion, other variables remaining unchanged. It is concluded that glucagon effects on functions of the gastric mucosa in the rat vary fundamentally, depending upon the environmental conditions.

Animals↗
PubMed2006

Hereditary diffuse leukoencephalopathy with spheroids: clinical, pathologic and genetic studies of a new kindred.

Hereditary diffuse leukoencephalopathy with spheroids (HDLS) is a rare autosomal dominant disorder characterized by cerebral white matter degeneration with axonal spheroids leading to progressive cognitive and motor dysfunction. We report clinical and pathological features, as well as molecular genetic analysis, of a family with HDLS. A pedigree consisting of 27 persons in 5 generations contained 6 affected individuals. Dementia and depression were common; two individuals presented with a syndrome resembling corticobasal degeneration (CBD). Postmortem neuropathologic evaluation of three affected individuals revealed enlargement of the lateral ventricles and marked attenuation of cerebral white matter, but preservation of white matter in brainstem and cerebellum, except for the corticospinal tract. Histopathologic studies showed a loss of myelinated fibers, lipid-laden macrophages and bizarre astrocytes, as well as abundant axonal spheroids that were immunoreactive for phosphorylated neurofilament protein and amyloid precursor protein (APP), but not alphaB-crystallin and variably with ubiquitin. By electron microscopy, axonal spheroids contained aggregates of intermediate filaments or of organelles that were predominantly vesicular and lamellar. The cerebral cortex had focal neuronal degeneration with alphaB-crystallin-immunoreactive ballooned neurons. In summary, the present report describes a previously unreported kindred with HDLS with individuals presenting as CBD. Immunohistochemistry for APP and alphaB-crystallin demonstrates distinctive neurodegeneration in cerebral axons and perikarya.

Adult↗
PubMed1979

Pain of first-trimester abortion: its quantification and relations with other variables.

Among 2,299 patients on whom first-trimester abortions were performed after administration of local anesthesia, 97 per cent reported experiencing some degree of pain. Independent ratings of the pain severity were obtained from the patients and also from the doctors and counselors who observed them. Although the rating procedures used by patients from those used by doctors and counselors, the three sources agreed significantly in evaluating pain levels of individual patients. Data from all three sources indicated that pain produced during the abortion procedure tended to be minor in severity. The ranking of relative painfulness of the eight stages of the aborton procedure based on average ratings obtained from doctors was nearly identical to that based on average ratings obtained from counselors. (Patients did not rate the separate stages.) On average, the patients rated the pain as being less than earache or toothache, but more than headache or bachache. The youngest patients experienced the most pain, and the oldest experienced the least. Both gestational age and cervical dilatation were related to pain in a curvilinear fashion, i.e., for both variables, patients in extreme categories experienced more pain than those in intermediate categories. Preprocedure fearfulness was positively related to intraoperative pain. No support was found for the expectation that oral administration of 5 mg. of diazepam reduces pain during this procedure.

Abortion, Induced↗
PubMed1987

Isolation and characterization of proteoglycans synthesized by adult human gingival fibroblasts in vitro.

The proteoglycans synthesized by fibroblasts derived from healthy human gingivae were isolated and characterized. The largest medium proteoglycan was excluded from Sepharose CL-4B but not from Sepharose CL-2B; it was recovered in the most-dense density gradient fraction and identified as a chondroitin sulfate proteoglycan. The medium contained two smaller proteoglycans; one contained predominantly chondroitin sulfate proteoglycan, while the other was comprised predominantly of dermatan sulfate proteoglycan and was quantitatively the major species. The largest proteoglycan in the cell layer fraction, excluded from both Sepharose CL-2B and Sepharose CL-4B, was found in the least-dense density gradient fraction and contained heparan sulfate and chondroitin sulfate proteoglycan. It could be further dissociated by treatment with detergent, suggesting an intimate association with cell membranes. Two other proteoglycan populations of intermediate size were identified in the cell layer extracts which contained variable proportions of heparan sulfate, dermatan sulfate, or chondroitin sulfate proteoglycan. Some small molecular weight material indicative of free glycosaminoglycan chains was also associated with the cell layer fraction. Carbohydrate analysis of the proteoglycans demonstrated the glycosaminoglycan chains to have approximate average molecular weights of 25,000. In addition, N- and O-linked oligosaccharides which were associated with the proteoglycans appeared to be sulfated in varying degrees.

Centrifugation, Density Gradient↗
PubMed1987

Specific suppression of the in vitro parent anti-hybrid reaction. II. Parameters influencing suppressor cell induction in the F1 hybrid.

In the accompanying paper (K. Kosmatopoulos et al., Cell. Immunol. 104, 319-334, 1987) we have reported that the spleens of B6D2F1 hybrids pretreated with B6 spleen cells 7 days earlier contain a cell which specifically suppresses the in vitro proliferative and cytotoxic B6 anti-B6D2F1 responses. The results we present here concern the in vivo conditions under which this suppressor cell can be induced. Suppressor cell activity appears early after the injection of B6 spleen cells (day +1), increases on Day 7, and disappears by Day 30; it is always detectable after the injection of 5 X 10(7) B6 spleen cells and never after the injection of 1.25 X 10(7) cells, the intermediate dose of 2.5 X 10(7) cells being followed by variable results. This variability is attributable to the age of B6 donor and B6D2F1 recipient mice, and suppression is never observed when 2.5 X 10(7) spleen cells from 6-week-old B6 mice are injected into 6-week-old B6D2F1 hybrids. The suppressor cell is induced by the injection of B6 spleen cells of the Thy-1+ Ly-1-2+ phenotype, even if they are irradiated at 1000 R just before their injection. Lymph node cells from B6 mice induce the suppressor cell, whereas thymocytes do not. Irradiation of B6D2F1 hybrids at 600 or 950 R does not prevent the induction of suppressor cell, nor does thymectomy. Moreover, in the thymectomized or 600 R-irradiated B6D2F1 animals suppression can be induced even by the injection of only 1.25 X 10(7) B6 spleen cells. This phenomenon of specific suppression is not limited to the B6-B6D2F1 genetic combination since it has been observed in all parent-hybrid combinations tested to date.

Animals↗
PubMed1995

Indirect effects in ecological interaction networks. II. The conjugate variable approach.

A new method called the conjugate variable approach for the analysis of indirect effects propagating through an ecosystem network is developed. For a given ecosystem of n species, the 2n variables representing the inflows and abundances of the n species are related in the n equations that define the system's steady states. There are 2n alternative ways of designating, for each species, either an inflow or an abundance variable as an independent variable and the other (i.e., its conjugate variable) as a dependent variable. Each of these alternative ways defines a unique configuration of constraints in the influence propagation through the ecosystem network. In particular, designating as independent variables the inflow variables of all but two focal species leaves their abundance variables free to change, thus leading to the evaluation of the total effect between the two focal species. On the other hand, choosing their abundance variables as independent variables to fix prohibits influence to pass through any of these intermediate species, thus selectively evaluating the direct effect between the two focal species. Any other way between these two extreme cases sets partial constraints on influence propagation, thus evaluating a partial effect between the two species. Four categories of effects between two species--inflow to abundance, abundance to abundance, inflow to inflow, and abundance to inflow--can be distinguished and explicitly evaluated in terms of community matrix elements.

Animals↗