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PubMed1984

Anthropometric and genetic distance between Gonds of Central India.

A morphological and genetic study was undertaken on five Gondi-speaking populations of Central India (Andhra Pradesh and Maharashtra States). There has been no systematic biological study on this large Dravidian-speaking tribal group, 4 million in number, amounting to 13% of the total tribal population of India. Data was collected on 16 anthropometric measurements and seven genetic markers (blood groups, hemoglobin, G6PD and plasma protein polymorphisms) on the Raj Gonds, Kolams, Manne, Koyas and Plains Maria Gonds. Various genetic distance measures such as Mahalanobis's D2 and Nei's and Sanghvi's measures and cluster analysis techniques were used to determine the relationship between these groups based on anthropometrics and genetic variables. The statistical analysis revealed the Gonds to be a heterogenous group in both morphology and genetic characteristics. The morphological and genetic distances between these five groups when projected graphically revealed that the spatial distribution of these Gonds generally corresponds to their present geographical distribution. However, the actual relationships among each of the Gond populations show differences when based on these two biological variables, the possible reasons for this being discussed in the paper. The emphasis of this study is on the importance of geographical proximity in producing morphological and genetic similarity between populations, brought about by a short distance as well as similar geographical factors (such as soil, terrain, flora, etc.) drawing these populations together under a common ecocultural umbrella.

Anthropometry↗
PubMed1985

Isolation by distance, linguistic similarity, and the genetic structure on Bougainville Island.

Previous research has revealed extensive genetic variation among villages on Bougainville, in the Solomon Islands. Using previously published gene frequency data for seven loci, the role of isolation by distance in structuring genetic variation on Bougainville was reanalyzed. Newer methods of kinship estimation show that earlier estimates of the isolation by distance parameters were low. The fit of the model is highly significant (R2 = 0.409; P less than 0.001), and the parameter estimates indicate high isolation: a = 0.0538, b = 0.1978, L = -0.0057. Several methods of residual analysis were applied in order to determine factors affecting the fit of the model. Linguistic similarity has a significant effect on genetic variation once the effects of geographic distance are taken into account. Population-specific deviations from the expected model may be explained, in part, in terms of population history. Compared to other human populations, Bougainville Island shows an even greater among-group variation than has been suggested previously.

Gene Frequency↗
PubMed1985

Comparison of distance matrices in studies of population structure and genetic microdifferentiation: quadratic assignment.

Questions concerning the relative effects of various evolutionary forces in molding the genetic variability exhibited by groups of human populations have typically been investigated by comparing a variety of genetic and cultural/historical "distance" matrices. A major methodological difficulty has been the lack of formal testing procedures with which to assess the degree of confirmation or disconfirmation of an estimated measure of relationship between such matrices. In this paper, we examine a very flexible matrix combinatorial procedure which generates statistical significance levels for correlational measures of pattern similarity between distance matrices. A recent generalization of the basic procedure to the three-matrix case allows questions concerning which of two matrices best fits a third matrix to be formally tested. Applications of these hypothesis testing and inference procedures to two separate sets of genetic, geographic, and cultural distance matrices illustrates their potential for finally solving a long-standing problem in anthropological genetics.

Anthropometry↗
PubMed1987

Isolation by distance in Middle Dalmatia-Yugoslavia.

Parameters of Malécot's isolation-by-distance model are estimated for biological (anthropometric head and body dimensions, morphometric dimensions of metacarpal bones, quantitative and qualitative dermatoglyphic traits, and physiological/cardiorespiratory/variables) and linguistic distances and migrational kinship on the island of Korcula and the Peljesac peninsula in Middle Dalmatia, Croatia, Yugoslavia. Resulting parameters and the fit of the model are compared, for both regions, as well as with results of similar analysis in other parts of the world. The fit of the model is highly significant for migrational kinship and linguistic distances and less so for biological traits. Differences between these two populations, which live under basically similar ecological conditions, are explained by variation in biological and sociocultural history.

Adult↗
PubMed1990

Skeletal biological distance studies in American physical anthropology: recent trends.

Biological distance analysis, the dominant type of skeletal biological research during the 19th century, has become less visible in recent years. Although the proportion of American Journal of Physical Anthropology articles and published abstracts focusing on biodistance has remained fairly constant over the three decades between 1955 and 1985, the proportion of biodistance contributions relative to other skeletal biology studies has decreased. Emphasis in skeletal biology has shifted from the analysis of biological variation to investigations of health and diet, and within biodistance studies methodological issues have assumed prominence over purely analytical approaches. This paper investigates trends in biological distance analysis through a survey of articles and meetings abstracts published in the American Journal of Physical Anthropology from 1955 to 1985. The survey provides the historical context for five symposium papers on skeletal biological distance presented at the 1986 meeting of the American Association of Physical Anthropologists.

Anthropology, Physical↗
PubMed1993

Human dental arch shape evaluated by euclidean-distance matrix analysis.

Form differences between biological structures can be evaluated using several approaches. When landmark data are available, a recently proposed method (euclidean-distance matrix analysis) seems to be able to differentiate between size and shape differences. This method also localizes those areas which differ most between the two structures. We have applied it to analyze the sexual dimorphism in dental arch form in a sample of 50 men and 45 women. Subjects ranged in age between 20 and 27 years, and had sound dentitions. Fourteen landmarks, corresponding to the centers of gravity (centroids) of the occlusal surfaces of all permanent teeth (right second molar to left second molar), were individualized on the dental casts of subjects. All the possible linear distances between pairs of teeth were computed, thus creating four mean form matrices (one for each arch within sex). Gender differences were tested by using euclidean-distance matrix analysis. No significant differences were demonstrated in the shape of arches, while male arches proved to be slightly bigger than female arches.

Adult↗
PubMed2002

Comparison of three different ways of measuring distances between residences and high voltage power lines.

The aim of this study was to evaluate whether distance data based on calculations by use of digitalized geographical information systems (GIS) and distance data based on measurements on 1:5000 maps agree sufficiently with on site distance measurements to be used as input to magnetic field calculations in epidemiological studies. The analysis were performed by use of weighted kappa (kappa(w)) statistical method described by Bland and Altman for comparison of measures of agreement. Map measurements showed better agreement with on site measurements than GIS calculations did. However, we consider both methods appropriate for use in larger epidemiological studies if the results are interpreted with caution. GIS calculations have the advantage of being both time and cost saving.

Electromagnetic Fields↗
PubMedDate not supplied

Conformational studies of cyclic peptide structures in solution from 1H-Nmr data by distance geometry calculation and restrained energy minimization.

The three-dimensional structure of a cyclic bouvardin analogue, cyclo (-Pro-MeTyr-Ala-MeTyr-MeTyr-D-Ala-) has been determined by distance geometry calculation and restrained energy minimization from nmr data. The preparation of the input for the distance geometry calculations, the modification of the amino acid library, and the analysis of the structures were done with the aid of a recently developed software package, GEOM. A great variety of different initial structures were explored to check the uniqueness of the determined solution structure. Calculations with 500 different initial structures and two different strategies led to a uniquely determined backbone conformation with a root mean square deviations value of 0.4 A. The backbone structure consists of two beta-turns, a beta-II turn at Pro1-MeTyr2, and a beta-VI turn at MeTyr4-MeTyr5. The efficiency of the two calculation strategies were compared in order to propose an optimal means for performing distance geometry calculations with cyclic structures.

Amino Acid Sequence↗
PubMed2005

Triplet-triplet energy transfer controlled by the donor-acceptor distance in rigidly held palladium-containing cofacial bisporphyrins.

Eleven new complexes, including mono-, heterobi-, and homobimetallic cofacial bisporphyrins, (Pd)H2DPS, (M)H2DPX, (M)H2DPB, (PdZn)DPS, (PdZn)DPX, (Pt)2DPX, (M)2DPB (M = Pd, Pt), and (Pt)P (DPS4- = 4,6-bis[5-(2,8,13,17-tetraethyl-3,7,12,18-tetramethylporphyrinyl)]dibenzothiophene tetraanion, DPX(4-) = 4,5-bis[5-(2,8,13,17-tetraethyl-3,7,12,18-tetramethylporphyrinyl)]-9,9-dimethylxanthene tetraanion, DPB4- = 1,8-bis[5-(2,8,13,17-tetraethyl-3,7,12,18-tetramethylporphyrinyl)]biphenylene tetraanion, P2- = 5-phenyl-2,8,13,17-tetraethyl-3,7,12,18-tetramethylporphyrin dianion) have been synthesized and characterized. The photophysical properties of the donor (M)P (M=Pd or Pt, P=porphyrin chromophore) and the acceptor (free base H(2)P or (Zn)P) depend on the C(meso)-C(meso) distance and the presence of a heavy atom such as Pd(II) or Pt(II). The data were compared with those for the known compounds (Pd)2DPS, (Pd)2DPX, H4DPS, H4DPX, H4DPB, (Pd)P, (Zn)P, and H(2)P. The rate constants for triplet-triplet energy transfer (k(ET)) were measured for the heterobimetallic (PdZn) and monometallic [(M)H2] derivatives (M=Pd, Pt). The fluorescence lifetimes (Deltatau(F)) of the acceptors decrease as a result of the heavy-atom effect, and vary as follows: (Pd)H2DPS<<(Pd)H2DPX approximately (Pd)H2DPB. The k(ET) values calculated according to the equation k(ET)=(1/tau(emi)-1/tau(emi) (0)), where tau(emi) (0) is the emission lifetime of the homobimetallic bisporphyrins (no ET occurs), are equal to 0, 247+/-57 and 133+/-52 s(-1) for DPS, DPX, and DPB, respectively, in the (Pd)H(2) series. These measurements allowed the range of distance over which the Dexter mechanism for T(1)-T(1) energy transfer ceases to operate to be determined. This distance is somewhere between 4.3 and 6.3 A, in agreement with our recent findings on singlet-singlet energy transfer. During the course of this study, the X-ray crystal structure for (Pd)H2DPX was obtained; triclinic (P1), a = 11.1016(1), b = 14.9868(2), c = 20.6786(3) A, alpha = 102.091(1), beta = 100.587(1), gamma = 101.817(1) degrees , V = 3199.19(7) A(3), Z = 2.

Crystallography, X-Ray↗
PubMed2005

Contributions of the distance-dependent reorganization energy and proton-transfer to the hole-transfer process in DNA.

A kinetic study of the single-step hole transfer in DNA was performed by measuring time-resolved transient absorption. DNA molecules with various sequences were designed and conjugated with naphthalimide (NI) and phenothiazine (PTZ) to investigate the sequence and distance dependence of the single-step hole transfer between guanines (Gs). Hole injection into DNA was accomplished by excitation of the NI site with a 355 nm laser pulse, and the kinetics of the hole-transfer process were investigated by monitoring the transient absorption of the PTZ radical cation (PTZ.+). Kinetic analysis of the time profile of PTZ.+ based on the kinetic model showed that the distance dependence of the hole-transfer process was significantly influenced by the DNA sequence. Results of temperature- and isotope-effect experiments demonstrated that the activation energy increased as the number of bridge bases separating the Gs increased. This is because of the distance-dependent reorganization energy and contribution of the proton-transfer process to the hole transfer in DNA.

DNA↗
PubMed2007

Long-range-distance NMR effects in a protein labeled with a lanthanide-DOTA chelate.

A two-thiol reactive lanthanide-DOTA (1,4,7,10-tetraazacyclododecane-N,N',N'',N'''-tetraacetic acid) chelate, CLaNP-3 (CLaNP=caged lanthanide NMR probe), was synthesized for the rigid attachment to cysteine groups on a protein surface, and used to obtain long-range-distance information from the {15N,1H} HSQC spectra of the protein-lanthanide complex. The DOTA ring exhibits several isomers that are in exchange; however, single resonances were observed for most amide groups in the protein, allowing determination of a single, apparent magnetic-susceptibility tensor. Pseudocontact shifts caused by Yb-containing CLaNP-3 were observed for atoms at 15-35 A from the metal. By using Gd-containing CLaNP-3, relaxation effects were observed, allowing distances up to 30 A from the paramagnetic center to be determined accurately. Similar results were obtained with a Gd-DTPA (diethylene-triaminepentaacetic acid) chelate, CLaNP-1, bound in the same bidentate manner to the protein. This study demonstrates that bidentate attachment of a paramagnetic probe enables determination of long-range distances.

Chelating Agents↗
PubMed1990

Mother and sibling discrimination at a distance by three- to seven-day-old lambs.

This study examined some aspects of the developmental phase of social bonding in newborn lambs. In Experiment 1, 3-day-old Merino lambs (singles and twins) were tested in a 2-choice situation for mother discrimination at a distance. In Experiment 2, the ability of twins to discriminate their siblings at a distance was studied 3 and 7 days after birth. When released at 9 m from two postparturient ewes after a latency of 30 s, which allowed the lambs to hear and to see both animals, most lambs chose to run and to stay with their own mothers before the end of the 2-min test (Experiment 1). There was no difference between singles and twins, nor between males and females in their distant discriminative ability. However, twins were initially undecided, slower to reach their mothers, and spent significantly less time with them. When the same testing procedure was used for sibling discrimination, most 3-day-old twins went to a lamb, but the proportion of lambs reaching the sibling first did not differ significantly from random, and the time spent near either lamb was similar (Experiment 2). During these tests, female lambs performed better than males. When tested 7 days after birth, all twins reached a lamb and a high proportion of them chose to go to the sibling first. They also spent most of the time near it. These results demonstrate that mother discrimination from a distance is well established in 3-day-old lambs and sibling discrimination takes longer to develop but has occurred by 7 days of age.

Aging↗
PubMed2001

Eating disorders and health in elite women distance runners.

OBJECTIVES: To examine the presence of eating disorder syndromes in elite women distance runners in the United Kingdom and any associated differences in training, dieting, general health, and well-being. METHOD: Athletes were selected from the top of their respective ranking lists for all middle and long-distance races in 1996/1997. All running disciplines were included (track, road, cross-country, and fell/mountain running). Athletes were sent the Eating Disorders Examination Questionnaire and a questionnaire on demographics, athletic training, diet, and health. Of the 226 athletes identified, 181 (81%) completed and returned the questionnaires. RESULTS: Twenty-nine athletes (16%) had an eating disorder at the time of the study (7 had anorexia nervosa [AN], 2 had bulimia nervosa [BN], and 20 had eating disorders not otherwise specified [EDNOS]) and a further 6 had received previous treatment. Comparing the eating disorder group with the rest of the sample showed no difference in age, height, preferred race distance, or the number of hours/week spent training. However, they had a significantly lower body mass index (BMI), lower self-esteem, and poorer mental health. Current and past dieting were significantly more common in the eating disorder group. DISCUSSION: The levels of AN and EDNOS are higher than would be expected in similarly aged, nonathletic women. The demands for leanness rather than exercise intensity appear to be the main risk in these elite runners. The early detection and prevention of eating disorders in women athletes should have high priority.

Adult↗
PubMed2005

Travel distance and attrition in outpatient eating disorders treatment.

OBJECTIVE: The purpose of this study was to investigate the impact of the distance patients had to travel for treatment on attendance patterns and treatment attrition. METHOD: Contact information, clinical records, and/or appointment records of 209 adult patients presenting to an outpatient eating disorder treatment center over a specific period of time were reviewed. Information was obtained on demographics, diagnosis, number of appointments attended, cancelled, and failed, and termination status. Patients were classified as treatment completers or dropouts and compared on demographic, diagnostic, attendance, and distance to treatment site variables. RESULTS: Treatment completer and dropout groups did not differ significantly on demographic variables, with the exception of employed patients being more likely to drop out of treatment. Although not statistically significant, patients diagnosed with bulimia nervosa (BN) and eating disorder not otherwise specified (EDNOS) were more likely to drop out of treatment prematurely. Surprisingly, distance traveled to the treatment site was not significantly different between groups and did not appear to significantly impact attendance patterns. CONCLUSION: Results of this archival investigation were unexpected and likely limited by the design. Results can be useful in understanding motivational factors inherent in noncompliance and premature termination of treatment. A prospective study including fine-grained analysis of variables associated with eating disorder treatment attrition is indicated.

Adolescent↗
PubMed2006

Influence of electric field intensity, ionic strength, and migration distance on the mobility and diffusion in DNA surface electrophoresis.

In order to increase the separation rate of surface electrophoresis while preserving the resolution for large DNA chains, e.g., genomic DNA, the mobility and diffusion of Lambda DNA chains adsorbed on flat silicon substrate under an applied electric field, as a function of migration distance, ionic strength, and field intensity, were studied using laser fluorescence microscope. The mobility was found to follow a power law with the field intensity beyond a certain threshold. The detected DNA peak width was shown to be constant with migration distance, slightly smaller with stronger field intensity, but significantly decreased with higher ionic strength. The molecular dynamics simulation demonstrated that the peak width was strongly related with the conformation of DNA chains adsorbed onto surface. The results also implied that there was no diffusion of DNA during migration on surface. Therefore, the Nernst-Einstein relation is not valid in the surface electrophoresis and the separation rate could be improved without losing resolution by decreasing separation distance, increasing buffer concentration, and field intensity. The results indicate the fast separation of genomic DNA chains by surface electrophoresis is possible.

Bacteriophage lambda↗
PubMed1994

Childhood cancer incidence in relation to distance from the former nuclear testing site in Semipalatinsk, Kazakhstan.

Rates of childhood cancer between 1981 and 1990 in the 4 administrative zones of Kazakhstan were studied to assess the relationship, if any, with distance from nuclear testing sites. Risk of various cancers among children aged 14 years or younger were estimated in relation to distance from (1) a site where testing in air was performed before 1963, (2) a site where underground testing took place thereafter, and (3) a reservoir, known as "Atom Lake," created by 4 nuclear explosions in 1965. Risk of acute leukaemia rose significantly with increasing proximity of residence to the testing areas, although the absolute value of the risk gradient was relatively small. The relative risk for those living less than 200 km from the air-testing site was 1.76 compared with those living 400 km or more away from the site. Similar relative risks were observed for the underground site and "Atom Lake." There was also some evidence of increased risk of brain tumours in association with proximity to the test sites. In 2 of the 4 zones studied, there was substantial regional variation in acute leukaemia rates which was not attributable to distance from the test site. The findings may be affected by potential confounders, notably urban/rural status and ethnic factors.

Adolescent↗
PubMed1985

Yeast mRNA initiation sites are determined primarily by specific sequences, not by the distance from the TATA element.

We present evidence suggesting that accurate mRNA initiation in yeast cells, unlike their higher eukaryotic counterparts, is determined primarily by specific sequences downstream from the TATA element. First, changing the distance between the his3 TATA element and the initiation region does not affect the sites of initiation or the level of RNA. Second, reciprocal his3-ded1 and ded1-his3 hybrid promoters containing the upstream and TATA elements of one gene fused to the mRNA coding region of the other gene initiate transcription at sites defined by wild-type mRNA coding sequences, not by the distance from the TATA element. Third, when the his3 or ded1 promoter region is fused to position +2 of the his3 gene, transcripts initiated from a position equivalent to +1 are not observed. The results also suggest that the spacing between the TATA element and initiation site is relatively flexible; distance ranging from 40 to 90 bp appear to be functionally acceptable.

Base Sequence↗
PubMed1995

A novel naturally occurring hybrid gene encoded by a plant RNA virus facilitates long distance virus movement.

We recently identified a new cucumovirus-specific gene (2b) which is encoded by RNA 2 of the cucumber mosaic cucumovirus (CMV) tripartite RNA genome and whose coding sequence overlaps the C-terminal 69 codons of ORF 2a encoding the RNA polymerase protein. We have now found that although a CMV mutant lacking ORF 2b accumulated in the inoculated cotyledons of cucumber plants, it was unable to spread systemically, demonstrating involvement of 2b in long distance movement. The same mutant infected tobacco systemically with a much reduced virulence and delayed appearance of symptoms, indicating that 2b may contribute to long distance movement in this host. Deletion of the overlapping C-terminal part of ORF 2a did not change infectivity of the mutant in either host species, ruling out 2a mutation as the reason for the change of phenotype. Further infectivity studies with mutants containing partial deletions in ORF 2b further supported the conclusion that 2b encodes a host-specific long distance movement function. Sequence analysis revealed that 2b may represent a novel naturally occurring hybrid gene important to the evolutionary formation of the cucumovirus group and that it could provide a genetic basis for the wide host range of these viruses.

Base Sequence↗