Population trends of forest birds in Missouri, USA: Comparison of point count data with predictions from the BBS [abstract]

Abstract only availableLong-term population size trends of Neotropical migrants and other forest birds are of primary concern for conservation biologists. The Breeding Bird Survey (BBS) has become an important tool for biologists in estimating population trends, but because surveys are conducted only along roads, its utility for forest interior species may be limited. We analyzed a long term (1991-2006) point count data set from the interior of three forested sites in central Missouri and compared our trend estimates to BBS trends for the state of Missouri. Using a mixed model analysis of variance with year as a fixed effect and point as a random effect, we generated trend estimates for thirteen species. Results/Conclusions Five species (38%) exhibited statistically significant negative trends indicating species decline, four species (31%) exhibited positive trends indicating that populations increased, three species (23%) exhibited no significant trend, and data from one species did not adequately fit the model. Of the nine species with significant trends in our point count data, seven (78%) had trends that were qualitatively similar to those generated from BBS data. However, for both of the species with contrasting trends, model predictions were strongly different. Our results suggest that the accuracy of BBS trends for forest interior birds may be species specific. We hope to strengthen our conclusions by incorporating point count data from other field sites and by controlling for observer effects in future analyses.NSF Undergraduate Mentoring in Environmental Biolog

Reproductive Success of Eastern Bluebirds (Siala sialis) on Suburban Golf Courses

Understanding the role of green space in urban—suburban landscapes is becoming critical for bird conservation because of rampant habitat loss and conversion. Although not natural habitat, golf courses could play a role in bird conservation if they support breeding populations of some native species, yet scientists remain skeptical. In 2003–2009, we measured reproduction of Eastern Bluebirds (Siala sialis) in Virginia on golf courses and surrounding reference habitats, of the type that would have been present had golf courses not been developed on these sites (e.g., recreational parks, cemeteries, agriculture land, and college campus). We monitored \u3e650 nest boxes and 2,255 nest attempts (n = 1,363 golf course, n = 892 reference site). We used an information-theoretic modeling approach to evaluate whether conditions on golf courses affected timing of breeding, investment, or nest productivity compared with nearby reference sites. We found that Eastern Bluebirds breeding on golf courses reproduced as well as those breeding in other disturbed habitats. Habitat type had no effect on initial reproductive investment, including date of clutch initiation or clutch size ( = 4 eggs). During incubation and hatching, eggs in nests on golf courses had higher hatching rates (80%) and brood sizes ( = 4.0 nestlings brood-1) than nests on reference sites (75% hatching rate; = 3.8 nestlings brood-1). Mortality of older nestlings was also lower on golf courses and, on average, golf course nests produced 0.3 more fledglings than nests on reference sites. Thus, within a matrix of human-dominated habitats, golf courses may support productive populations of some avian species that can tolerate moderate levels of disturbance, like Eastern Bluebirds

Case Reports1. A Late Presentation of Loeys-Dietz Syndrome: Beware of TGFβ Receptor Mutations in Benign Joint Hypermobility

Background: Thoracic aortic aneurysms (TAA) and dissections are not uncommon causes of sudden death in young adults. Loeys-Dietz syndrome (LDS) is a rare, recently described, autosomal dominant, connective tissue disease characterized by aggressive arterial aneurysms, resulting from mutations in the transforming growth factor beta (TGFβ) receptor genes TGFBR1 and TGFBR2. Mean age at death is 26.1 years, most often due to aortic dissection. We report an unusually late presentation of LDS, diagnosed following elective surgery in a female with a long history of joint hypermobility. Methods: A 51-year-old Caucasian lady complained of chest pain and headache following a dural leak from spinal anaesthesia for an elective ankle arthroscopy. CT scan and echocardiography demonstrated a dilated aortic root and significant aortic regurgitation. MRA demonstrated aortic tortuosity, an infrarenal aortic aneurysm and aneurysms in the left renal and right internal mammary arteries. She underwent aortic root repair and aortic valve replacement. She had a background of long-standing joint pains secondary to hypermobility, easy bruising, unusual fracture susceptibility and mild bronchiectasis. She had one healthy child age 32, after which she suffered a uterine prolapse. Examination revealed mild Marfanoid features. Uvula, skin and ophthalmological examination was normal. Results: Fibrillin-1 testing for Marfan syndrome (MFS) was negative. Detection of a c.1270G > C (p.Gly424Arg) TGFBR2 mutation confirmed the diagnosis of LDS. Losartan was started for vascular protection. Conclusions: LDS is a severe inherited vasculopathy that usually presents in childhood. It is characterized by aortic root dilatation and ascending aneurysms. There is a higher risk of aortic dissection compared with MFS. Clinical features overlap with MFS and Ehlers Danlos syndrome Type IV, but differentiating dysmorphogenic features include ocular hypertelorism, bifid uvula and cleft palate. Echocardiography and MRA or CT scanning from head to pelvis is recommended to establish the extent of vascular involvement. Management involves early surgical intervention, including early valve-sparing aortic root replacement, genetic counselling and close monitoring in pregnancy. Despite being caused by loss of function mutations in either TGFβ receptor, paradoxical activation of TGFβ signalling is seen, suggesting that TGFβ antagonism may confer disease modifying effects similar to those observed in MFS. TGFβ antagonism can be achieved with angiotensin antagonists, such as Losartan, which is able to delay aortic aneurysm development in preclinical models and in patients with MFS. Our case emphasizes the importance of timely recognition of vasculopathy syndromes in patients with hypermobility and the need for early surgical intervention. It also highlights their heterogeneity and the potential for late presentation. Disclosures: The authors have declared no conflicts of interes

Finishing the euchromatic sequence of the human genome

The sequence of the human genome encodes the genetic instructions for human physiology, as well as rich information about human evolution. In 2001, the International Human Genome Sequencing Consortium reported a draft sequence of the euchromatic portion of the human genome. Since then, the international collaboration has worked to convert this draft into a genome sequence with high accuracy and nearly complete coverage. Here, we report the result of this finishing process. The current genome sequence (Build 35) contains 2.85 billion nucleotides interrupted by only 341 gaps. It covers ∼99% of the euchromatic genome and is accurate to an error rate of ∼1 event per 100,000 bases. Many of the remaining euchromatic gaps are associated with segmental duplications and will require focused work with new methods. The near-complete sequence, the first for a vertebrate, greatly improves the precision of biological analyses of the human genome including studies of gene number, birth and death. Notably, the human enome seems to encode only 20,000-25,000 protein-coding genes. The genome sequence reported here should serve as a firm foundation for biomedical research in the decades ahead

孵化成功率的时空变化和雏鸟性别比例追踪鸣鸟杂交地带的快速移动

Hybridization often occurs at the parapatric range interface between closely related species, but fitness outcomes vary: hybrid offspring exhibit diverse rates of viability and reproduction compared with their parental species. The mobile hybrid zone between two chickadee congeners (Poecile atricapillus #Poecile carolinensis) has been well studied behaviorally and genetically, but the viability of hybrids and the underlying mechanisms contributing to hybrid fitness have remained unclear. To better characterize the fitness costs of hybridization in this system, we analyzed 21 years of data from four sites, including more than 1,400 breeding attempts by the two species, to show that rates of hatching success changed substantially as the zone of hybridization moved across the landscape. Admixture-associated declines in hatching success correlated with reduced proportions of heterogametic (female) offspring, as predicted by Haldane’s rule. Our data support an underlying mechanism implicating genetic admixture of the homogametic (male) parent as the primary determinant of offspring sex ratio, via incompatibilities on the hemizygous Z chromosome. Our long-term study is the first to directly measure changes in fitness costs as a vertebrate hybrid zone moves, and it shows that changes in these costs are a way to track the distribution of a hybrid zone across the landscape.摘要：物种杂交通常出现在亲缘关系密切的物种之间的邻域边界范围内，但适应性结果不尽相同：与他们的双亲物种相比，杂交后代呈现出不同的成活率和繁殖率。移动杂交区域内的两种同类山雀 - 黑顶山雀和卡罗莱纳山雀 （Poecile atricapillus × Poecile carolinensis） 的行为和基因都已经得 到很好的研究，但杂交成活 力以及促成杂交后代适应性的潜在机制仍不清楚。为了更好的描述该系统中杂交的适应性代价，我们分析了来自四个地点21年的数据，包括两个物种之间超过1400次的育种尝试，从而表明随着杂交区在整个景观的变化，孵化成功率也发生了显著地变化。正如霍尔丹规则所预测的一样, 与杂交混合率相关的孵化成功率递减和异 配子（雌性）后代的比例降低呈相 关。我们的数据佐证一个潜在的机制，即同配 子（雄性）亲本遗传基因混合通过纯合子Z 染色体上 出现的不相容性，而成为后 代性别比例主要决定因素。我们的长期研究首次直接测量了随着脊椎动物杂交区域移动的适应性代价变化，并证明了这些代价的变化是追踪杂交区域在整个景观中分布的一种方式。Fil: Driver, Robert J.. Villanova University; Estados Unidos. East Carolina University; Estados UnidosFil: Ferretti, Valentina. Villanova University; Estados Unidos. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Ciudad Universitaria. Instituto de Ecología, Genética y Evolución de Buenos Aires. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Instituto de Ecología, Genética y Evolución de Buenos Aires; ArgentinaFil: Burton, Emily S.. Villanova University; Estados UnidosFil: McCoy, Michael W.. East Carolina University; Estados UnidosFil: Cornell Duerr, Kerri L.. Villanova University; Estados UnidosFil: Curry, Robert L.. Villanova University; Estados Unido

Aspartate 458 of human glutathione synthetase is important for cooperativity and active site structure

Human glutathione synthetase (hGS) catalyzes the second ATP-dependent step in the biosynthesis of glutathione (GSH) and is negatively cooperative to the γ-glutamyl substrate. The hGS active site is composed of three highly conserved catalytic loops, notably the alanine rich A-loop. Experimental and computational investigations of the impact of mutation of Asp458 are reported, and thus the role of this A-loop residue on hGS structure, activity, negativity cooperativity and stability is defined. Several Asp458 hGS mutants (D458A, D458N, D458R) were constructed using site-directed mutagenesis and their activities determined (10, 15 and 7% of wild-type hGS, respectively). The Michaelis-Menten constant (K(m)) was determined for all three substrates (glycine, GAB, ATP): glycine K(m) increased by 30 - 115 fold, GAB K(m) decreased by 8 - 17 fold, and the ATP K(m) was unchanged. All Asp458 mutants display a change in cooperativity from negative cooperativity to non-cooperative. All mutants show similar stability as compared to wild-type hGS, as determined by differential scanning calorimetry. The findings indicate that Asp458 is essential for hGS catalysis and that it impacts the allostery of hGS