Keeping Meta-Analyses Hygienic During the COVID-19 Pandemic

Despite the massive distribution of different vaccines globally, the current pandemic has revealed the crucial need for an efficient treatment against COVID-19. Meta-analyses have historically been extremely useful to determine treatment efficacy but recent debates about the use of hydroxychloroquine for COVID-19 patients resulted in contradictory meta-analytical results. Different factors during the COVID-19 pandemic have impacted key features of conducting a good meta-analysis. Some meta-analyses did not evaluate or treat substantial heterogeneity (I2 > 75%); others did not include additional analysis for publication bias; none checked for evidence of p–hacking in the primary studies nor used recent methods (i.e., p-curve or p-uniform) to estimate the average population-size effect. These inconsistencies may contribute to contradictory results in the research evaluating COVID-19 treatments. A prominent example of this is the use of hydroxychloroquine, where some studies reported a large positive effect, whereas others indicated no significant effect or even increased mortality when hydroxychloroquine was used with the antibiotic azithromycin. In this paper, we first recall the benefits and fundamental steps of good quality meta-analysis. Then, we examine various meta-analyses on hydroxychloroquine treatments for COVID-19 patients that led to contradictory results and causes for this discrepancy. We then highlight recent tools that contribute to evaluate publication bias and p-hacking (i.e., p-curve, p-uniform) and conclude by making technical recommendations that meta-analyses should follow even during extreme global events such as a pandemic.

Familial Mediterranean fever research activity in the Arab World: the need for regional and international collaborations

Background: Familial Mediterranean fever (FMF) is an autoinflammatory, multisystem disease affecting the populations of the Mediterranean basin. Aim: The aim of this study was to assess the research input of Arab countries on FMF between 2004 and 2019. Methods: The Medline database (PubMed) was accessed for FMF-related publications. The number of publications was normalized to average: population size, GDP and number of physicians for every country. VOSViewer was used to create a co-occurrence bibliographic map. Results: Between 2004 and 2019, 69 articles relating to FMF were published in the Arab world, accounting for 0.03% of the total number of publications originating in Arab countries, and 3.60% of all articles relating to FMF worldwide. After normalizing to average population size, GDP and number of physicians, Lebanon ranked first with 4.44, 0.64 and 1.99 publications per million persons respectively. Moderate positive correlations were found between number of publications and average population size (r = 0.385) and average number of physicians (r = 0.513). Half of the articles were published in journals ranked Q1 and Q2. An abundance of keywords relating to genetics hint at a main focus on the genetic aspect of the disease. Conclusion: The low number of publications could be a result of the absence of research funding and the political and military instability in the Arab world. Given that many articles were published in high quality journals, Arab countries should focus on providing a clinical aspect to their studies and working on regional and international collaborations.

“New” rural settlements – former urban-type settlements

Since the 1920s, when the notion of urban-type settlement (UTS) was introduced in Russia, and until the 1980s the number of UTSs was constantly increasing. But since the 1990s, their rapid decline began, and by 2019 more than a third of them were transformed into rural settlements. In this article, the authors try to find out what the new villages the former UTSs are; where they are located; what their functions (largely lost) are, and what the specific features of their population are. From 1989 to 2010, the processes of transformation of UTSs into rural settlements administratively increased rural population of Russia by 2.4 mln people and held back the growth of the urban population share, which increased only slightly from 73.4 to 73.7%. When comparing the census data of 1989 and 2010 in many regions, the administrative ruralization radically changed the dynamics of the population: instead of a real decrease in the number of rural residents, Census-2010 showed the increase of rural population. Former UTSs are losing population more rapidly than the rural areas of their municipal districts, and the most intensive outflow is in logging settlements, centers of construction and colonies-settlements. The average population size of the former UTSs is minimal in the North of European Russia and the Far North, and maximum in the European South and in the Ural-Volga area, where the former UTSs-district centers are mostly concentrated, in which change of their status was purely formal.

Feeds and fodder dynamics in selected river basins of Bangladesh

A baseline survey was conducted with the objectives to determine seasonal availability, utilization of feeds and fodder resources and livestock production systems in different river basin areas and to identify the constraints of fodder production in selected river basins of Bangladesh. Based on cattle population, 2 upazilas from each of 10 districts were selected for household survey (HHS). A randomly selected 50 farmers from each upazila were considered for collecting information. After screening a total of 963 HHs were considered for statistical analyses. Results show that about 51%HHs were landless. Having an average population size of 3.3, about 99% HHs in the surveyed areas was keeping cattle, whereas, buffalo was not found in all regions which were found only in1.7% HHs with an average population size of 2.31 per buffalo keeper HH. Sheep was found only in about 1% HHs with an overall number of 3.22 per sheep keeper HH. About 16% HHs were keeping goats with an average size of 2.9 per sheep keeper HH. Significant differences on performance potentials were found both in native and crossbred cows among different regions. It was observed that all types of farm categories HHs reared cattle and most of them reared by tethering (around 23%) and free grazing (around 22%) management systems but semi-grazing was followed by around 14% HHs. Rest of the farmers followed different combinations of methods. Rice straw and naturally grown green grasses were the main roughages for feeding their cattle. About 95% HHs fed rice straw and about 81% HHs fed cut and carry green grass to their cattle. There were no seasonal variations on feeding rice straw but variations occurred for supplying cut and carry green grasses. Concentrates provided to animals in the surveyed areas were mainly rice polish, wheat bran, broken rice, pulse bran and mustard oil cake, among which rice polish and wheat bran were supplied by more HHs (about 93% and 75%, respectively). The variations of supplying concentrates among seasons were very negligible. Although, there were about 1.14% HHs who cultivated some fodder crops, they harvest grains for human consumption and residues for their cattle. However, high yielding varieties of fodders are very rarely cultivated by the farmers for feeding cattle in the riverside regions. The reason not to cultivate fodder and main constraint behind it was not accurately mentioned by the farmers. In the survey among different riverside regions, about48 different native green fodders were obtained in different agro-ecological zones, among which most available native green fodders were Durba, Badla, Kawn, Shama, Khesari, Gamma, Ura, Gobra, Shama and Maskalai. Most of the native grasses are grown more in summer and some others like Kawn, Khesari and Maskalai are grown in winter. Finally, it may be concluded that extensive fodder cultivation program by motivating farmers through training and demonstrating high yielding fodder crops are essential in the riverside regions for increasing productivity of livestock in the respective areas.Bang. J. Anim. Sci. 2017. 46 (3): 206-214

Descriptive study of an outbreak of equine sarcoid in a population of Cape mountain zebra (Equus zebra zebra) in the Gariep Nature Reserve

An outbreak of equine sarcoid occurred in a population of Cape mountain zebra (Equus zebra zebra) at the Gariep Nature Reserve located in the southern Free State Province of South Africa in 1996. The course of the outbreak during 1996 to 2003 is described. During this period the average population size was 69 animals. Initially (1996) all affected animals were removed from the population. New cases continued to manifest and the incidence varied between 4.6% and 17.6 %. Prevalence reached 24.7% in 2002. No sexual predilection was noticed in the 39 recorded cases. Of the affected individuals, 64 % had a single lesion and no animal had more than 4 lesions. In males, the majority of lesions occurred in the inguinal area (55.17 %), whereas in females they mostly occurred on the head and neck (41.38 %). Lesions can increase 260 % in size annually and may impede movement.

Population structure of the Sahiwal breed in Pakistan

The present study was undertaken to assist conservation and improvement schemes in the Sahiwal breed of cattle in Pakistan. A data set, consisting of records of 244 pure Sahiwal breeding bulls and 5247 cows, the latter representing about 80% of all recorded Sahiwal cows in Pakistan born during a period covering about 20 years, was analysed with regard to inbreeding, additive relationships, effective population size and generation intervals. Average inbreeding coefficients of 1224 cows and 49 bulls, for which at least the grandparents and great-grandsires were known, were 0·043 and 0·046, respectively. About two-thirds of the inbreeding was due to matings between animals with parents or grandparents in common. The mean additive relationship among the cows was 0·062, with within-herd averages ranging from 0·087 to 0·358. The average population size in a subdata set of recorded Sahiwal cattle from 1980 to 1984 was 1612, whereas the most likely estimate of the effective population size was about 30 animals for the same active breeding population. The study indicated the immediate need for an active conservation programme whereby the Sahiwal subpopulations of India and Kenya also should be involved.

A Stochastic Age-Structured Population Model of Striped Bass (Morone saxatilis) in the Potomac River

Deterministic age-structured models of fish populations neglect apparently stochastic fluctuations in the catch per unit effort of yearlings and of adult fish. We describe a model of an age-structured population in which the survival of eggs to yearlings fluctuates randomly, but all other age-specific rates of survival and of egg-laying are constant. For such a stochastic model, two measures of the long-term population growth rate are the average growth rate of the population size and the growth rate of the average population size. We compute both measures analytically for a simplified model representing only eggs and reproductive adults. For a model of the striped bass (Morone saxatilis) population spawning in the Potomac River, we compute both point and interval estimates of the growth rate of the average population size. We illustrate some statistical tests of the correctness of our stochastic model.

Constraints on the relative sizes of the cell populations in Hydra attenuata

The steady-state relative population sizes of the several cell populations in Hydra attenuata were examined. In contrast to the constant average population size ratios between groups of animals, these ratios vary within limits between individual animals within a group. By maintaining animals on different feeding regimes (number of shrimp larvae ingested per day), the steady-state population size ratios were altered. The kinds of changes that occurred in these ratios suggest where controls may be operating to maintain the steady-state population sizes.

EVOLUTION OF EXPERIMENTAL "MUTATOR" POPULATIONS OF DROSOPHILA MELANOGASTER

ABSTRACT The theory of evolution predicts that the rate of adaptation of a population is a function of the amount of genetic variation present in the population. This has been experimentally demonstrated in Drosophila populations in which genetic variability was increased either by mass hybridization of two gene pools, or by X-irradiation.—Mutator genes increase the spontaneous mutation rates of their carriers. We have now studied the effects of a third-chromosome mutator gene, mt, on the rate of adaptation of laboratory populations. Initially, experimental and control populations had similar genetic constitutions except for the presence or absence of the mt gene. The populations were maintained for 20–25 generations by "serial transfer" under conditions of very intense selection.—The number of flies produced per unit time remained constant throughout the experiment in the experimental as well as in the control populations. However, in the mutator-carrying populations the average longevity of the flies (and consequently the average population size) gradually decreased. Under the experimental conditions natural selection is unable to counteract completely the increased input of deleterious mutations due to the mt gene.

The louse populations of some cricetid rodents

In 1952 and 1953, 798 specimens of Peromyscus maniculatus, Microtus pennsylvanicus and Clethrionomys gapperi were examined for total louse populations. Two species of sucking lice, Hoplopleura acanthopus and H. hesperomydis, were found on these species. H. acanthopus was found almost exclusively on Microtus pennsylvanicus and Clethrionomys gapperi, and Hoplopleura hesperomydis was found almost exclusively on Peromyscus maniculatus.Contamination appears to account for the apparently abnormal associations. The rates of infestation varied from host to host and from year to year. In general the higher infestations were found on host populations which were stable or declining, and the lower rates were on hosts which were increasing in density. Microtus pennsylvanicus had the highest infestation rate followed by Peromyscus maniculatus, with Clethrionomys gapperi nearly free of lice.The age of the host apparently had little to do with rate of infestation or population size.The louse populations were made up of about equal numbers of adults and nymphs. The adult sex ratio was, in each sample, unbalanced in favour of the females.The average population size varied between sexes of host and years. The male hosts had a higher average population than the female.