During the anatomical dissection of the pelvis, a duplication of the uterine artery was identified unilaterally on the left side in a 59-year-old Korean female cadaver. The first uterine artery was ...found to arise directly from the anterior division of the internal iliac artery and supply the upper uterine body and tube. The second uterine artery shared a common stem with the superior and inferior vesical arteries, supplying the lower uterine body. The external diameter of each uterine artery at its origin on the left side was smaller than that of the right uterine artery. One vaginal artery was identified to arise from the left internal pudendal artery. Embryologically, a duplicated uterine artery could imply the presence of two primordial arteries separately supplying the cranial and caudal parts of the Müllerian duct during the early fetal period. This case of variational anatomy is noteworthy: clinicians could elucidate it and successfully perform uterine artery embolization or hysterectomy with minimal complications.
Knowledge of the anatomic variations in the pectineus muscle is important for vascular surgeons to minimize complications following surgical approach to the distal part of the deep femoral artery. ...During routine dissection of the thigh, variations in the bilateral pectineus muscles were identified in an 82-year-old male cadaver. On both sides, the superficial and deep layers of the pectineus were divided at its distal part, forming a triangular-shaped hiatus between them and the femur shaft. Distally, the tendon of the superficial part intermingled with the tendon of the adductor longus. The tendon of the deep part was inserted into the pectineal line. On the right side, the deep femoral artery and its first perforating artery passed through the hiatus. On the left side, the deep femoral artery pierced the hiatus, and then, the first perforating artery was branched from the deep femoral artery. No reported case has described a pectineal hiatus. The variations observed in this study are an ontogenetic vestige of the two different origins of the pectineus. The insertion of the superficial layer into the adductor longus tendon suggests a close relationship between these muscles during prenatal development. Surgeons should be aware of the variation to minimize injury to the pectineus muscle while approaching the deep femoral artery.
Climate change is contributing to biodiversity redistributions and species declines. However, cooler microclimate conditions provided by old‐growth forest structures compared with surrounding open or ...younger forests have been hypothesized to provide thermal refugia for species that are sensitive to climate warming and dampen the negative effects of warming on population trends of animals (i.e., the microclimate buffering hypothesis). In addition to thermal refugia, the compositional and structural diversity of old‐growth forest vegetation itself may provide resources to species that are less available in forests with simpler structure (i.e., the insurance hypothesis). We used 8 years of breeding bird abundance data from a forested watershed, accompanied with sub‐canopy temperature data, and ground‐ and LiDAR‐based vegetation data to test these hypotheses and identify factors influencing bird population changes from 2011 to 2018. After accounting for imperfect detection, we found that for 5 of 20 bird species analyzed, abundance trends tended to be less negative or neutral at sites with cooler microclimates, which supports the microclimate buffering hypothesis. Negative effects of warming on two species were also reduced in locations with greater forest compositional diversity supporting the insurance hypothesis. We provide the first empirical evidence that complex forest structure and vegetation diversity confer microclimatic advantages to some animal populations in the face of climate change. Conservation of old‐growth forests, or their characteristics in managed forests, could help slow the negative effects of climate warming on some breeding bird populations via microclimate buffering and possibly insurance effects.
In this study, we monitored breeding bird populations and microclimate temperatures from H.J. Andrews Experimental Forest for 8 years. We found that cooler microclimates can benefit birds like Hermit Warblers by reducing rates of decline or even resulting in positive trends for this declining species. In addition, we found that complex forests with more plant species and dead wood can reduce the negative effects of warmer temperatures on bird population trends for other species like Wilson's Warbler.
Microplastics (< 5 mm) have been found in marine ecosystems worldwide, even in Antarctic ecosystems. In this study, the stomach and upper intestines of 14 dead gentoo penguin (Pygoscelis papua) ...chicks were collected and screened for microplastics on King George Island, a gateway to Antarctic research and tourism. A total of 378 microplastics were identified by Fourier-transform infrared spectroscopy, with 27.0 ± 25.3 microplastics per individual. The detected number of microplastics did not increase with the mass of penguin chicks, suggesting no permanent accumulation of microplastics. However, the concentration of microplastics was much higher (9.1 ± 10.8 microplastics per individual within the size range 100-5000 μm) than the previously reported concentration in the penguin feces, and a greater number of smaller microplastics were found. Marine debris surveys near the breeding colony found various plastic (79.3%) to be the most frequent type of beached debris, suggesting that local sources of marine plastic waste could have contributed to microplastic contamination of penguin chicks being fed by parents that forage in nearby seas. This finding confirms the presence of microplastics in an Antarctic ecosystem and suggests the need for stronger waste management in Antarctica and a standardized scheme of microplastic monitoring in this once-pristine ecosystem.
The purpose of this study was to identify the frequency of pectineal hiatus and of pectineus innervations, including femoral, obturator, and/or accessory obturator nerves. Also, this study sought to ...detailed intramuscular nervous distributions, with a particular focus on the relationship of nerves in multi-innervated pectineus. One hundred (49 right and 51 left) thighs from 52 cadavers (25 men and 27 women) were dissected. The morphology and innervations of the pectineus were investigated. Modified Sihler’s whole-mount nerve-staining method was employed for visualization of the intramuscular nerve-distribution patterns of the pectineus. Variation of the pectineus forming a hiatus was identified in 18% of the specimens. The femoral innervations to the pectineus were identified in all specimens. Additional innervation either by the obturator or the accessory obturator branch to the pectineus was identified in 10% or 2% of specimens, respectively. No case of triple innervation to the pectineus was observed. In cases of dually innervated pectineus, two nerves formed a communication system inside the muscle. Among the three nerves supplying the pectineus, the femoral nerve branched more than the other two nerves and covered the greatest area in the muscle. The pectineal hiatus appears to be a common variation. The femoral nerve branch in a dually innervated pectineus is the dominant nerve component that supplies the muscle when considering frequency, branching pattern, and area, even though cooperation between two nerve components is implied. This study serves to advance the existing anatomical knowledge about the pectineus muscle, which is of clinical value.
Understanding anatomic variations in neurovascular structure inside the femoral triangle is crucial for regional anesthesiologists performing femoral nerve block. During routine dissection of a ...cadaver, an ascending branch of the lateral circumflex femoral artery with an anomalous course passing through the femoral nerve, specifically the posterior division, was identified inside the femoral triangle on the left thigh. The novel variation identified in this study occurred in an early stage of prenatal development. Recognition of this anatomic variation will be helpful for reducing unexpected complications during the femoral nerve block and the tensor fascia latae flap. Penetration of the posterior division of the femoral nerve by the arterial branch might cause pain or paresthesia of the medial aspect of the leg in the distribution of the saphenous nerve.
Climate change can alter and disrupt the phenology and phenological interaction between organisms from various trophic levels in forest ecosystems. In temperate forests, the breeding phenology of ...birds is correlated to local microclimate, especially spring temperature to match the timing of food availability. Recent studies revealed that the temperature warming is more pronounced in high-elevation areas (elevation-dependent warming), while the breeding phenology shift of birds in this condition needs further investigation. We studied the annual change in the egg-laying dates of varied tits (Poecile varius) and a pre-breeding temperature index in three plots located along with the elevational gradient in South Korea and a low-elevation plot in Japan. We found strong support for disproportionate rates of changes in higher elevation for warming trends in pre-breeding period and advances in egg-laying dates over the last decade. Next, we compared three segments of 36-year data from Akazu Research Forest. The evidence from pre-breeding temperature during 36 years indicates that we could detect the change in thermal environment and breeding phenology with longer years of data, especially in lower elevation regions. This result shows the need for long-term research to understand the change in local temperatures and the ecology of forest birds. Our study presents evidence of elevation-dependent phenological advance in avian breeding activities and discusses the need for systematic long-term research on multiple taxa and climatic drivers in Asia.
...although the primary audience for the rules we provide are new graduate students, we note that the principles we raise are broadly applicable to researchers in a wide range of disciplines. ...it ...is still important to have a thorough understanding of the background literature and the research question(s) that motivated data collection. ...rather than assuming that such an “inherited” study lacks room for improvement, we recommend that students critically examine the choices made in data collection, understand their strengths and weaknesses, and independently assess whether the resulting data are sufficient to address the research question(s) being examined. Units in the treatment group are subjected to an experimental manipulation, whereas those in the control group are not, and the average response across experimental units in the 2 groups is then compared. Because other factors are held constant, differences detected in the treatment group relative to the control group can be attributed to the experimental manipulation. ...the reasonable scope of inference for a research project is typically constrained by the realities of data collection. ...defining the scope of inference for a study involves thinking carefully about the chosen sampling approach, potential sources of bias, and acknowledging how they limit the generalizability of a study.
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DOBA, IZUM, KILJ, NUK, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK
Research hypotheses have been a cornerstone of science since before Galileo. Many have argued that hypotheses (1) encourage discovery of mechanisms, and (2) reduce bias—both features that should ...increase transferability and reproducibility. However, we are entering a new era of big data and highly predictive models where some argue the hypothesis is outmoded. We hypothesized that hypothesis use has declined in ecology and evolution since the 1990s, given the substantial advancement of tools further facilitating descriptive, correlative research. Alternatively, hypothesis use may have become more frequent due to the strong recommendation by some journals and funding agencies that submissions have hypothesis statements. Using a detailed literature analysis (N = 268 articles), we found prevalence of hypotheses in eco–evo research is very low (6.7%–26%) and static from 1990–2015, a pattern mirrored in an extensive literature search (N = 302,558 articles). Our literature review also indicates that neither grant success nor citation rates were related to the inclusion of hypotheses, which may provide disincentive for hypothesis formulation. Here, we review common justifications for avoiding hypotheses and present new arguments based on benefits to the individual researcher. We argue that stating multiple alternative hypotheses increases research clarity and precision, and is more likely to address the mechanisms for observed patterns in nature. Although hypotheses are not always necessary, we expect their continued and increased use will help our fields move toward greater understanding, reproducibility, prediction, and effective conservation of nature.
We use a quantitative literature review to show that use of a priori hypotheses is still rare in the fields of ecology and evolution. We provide suggestions about the group and individual‐level benefits of hypothesis use.
Paleopathological evidence for congenital and degenerative disorders of the lumbosacral vertebrae is informative about ancient individual lifeways and physical conditions. However, very few studies ...have focused on the paleopathology of the lumbosacral vertebrae in ancient skeletal series from East Asia. One reason for the lack of studies is that skeletal samples from East Asia are typically insufficient in size to represent populations for comparative studies within the continent. Here, we present the first comprehensive analysis of lumbosacral defects in an East Asian human skeletal sample, examining occurrences of spina bifida occulta (SBO), lumbosacral transitional vertebrae (LSTV), and spondylolysis in remains from Joseon tombs dating to the 16–18th centuries in Korea. In this study, we present an alternative methodology for understanding activities of daily life among ancient Koreans through paleopathological analysis.
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