bluuebunny/crossref_metadata_2025_split huggingface dataset:
Reproductive Performance of Seabirds: The Importance of Population and Colony Size
Authors: Hunt George L. , Eppley Zoe A. , Schneider David C. 
Published: September 2019

Abstract
We compared reproductive performance of five species of seabirds at two colonies, St. George Island (2.5 million birds) and St. Paul Island (250,000 birds), in the southeastern Bering Sea. All species had lower chick growth rates at the larger colony, and the differences were statistically significant in four species. Fledge weights of Common Murres (Uria aalge) on St. George Island were 84-88% of those on St. Paul. Average fledge weights of Thick-billed Murres (Uria lomvia) on St. George were only 74% of those for chicks from St. Paul. We found no significant differences in clutch size or breeding success between populations breeding at the two colonies. For three species, Black-legged Kittiwakes (Rissa tridactyla), Common Murres, and Thick-billed Murres, we extended our analysis to include published data from other colonies. We examined breeding performance as a function of colony size, population size (suggestive of intraspecific competition), and "effective colony size," the sum of the populations of species with considerable dietary overlap (suggestive of interspecific competition for food). We found consistently negative relationships between population size and several measures of breeding performance (clutch size, growth rate, fledge weight, and breeding success). In addition to the lower breeding success at colonies that support large populations, chicks from these colonies may be subject to higher postfledging mortality because of fledging at lower weights.
Search Tactics of Insectivorous Birds Foraging in an Australian Eucalypt Forest
Authors: Holmes Richard T. , Recher Harry F. 
Published: September 2019

Abstract
The different ways birds searched for food in an Australian Eucalyptus forest led them to detect and capture different kinds of prey. Five major searching modes were identified among 23 common, mostly insectivorous bird species. These were distinguished largely by the rates, distances, and angles moved by birds while foraging and by their prey-capture behavior. Some bird species typically moved slowly, visually examining substrates at relatively long distances, and then took flight to capture prey (e.g. whistlers, flycatchers, muscicapid robins, cuckoos). Others moved at more rapid rates and either gleaned small prey from nearby substrates (e.g. thornbills, treecreepers) or flushed insects that were then pursued (e.g. fantails). Two species (Eastern Shrike-Tit, Falcunculus frontatus; White-eared Honeyeater, Meliphaga leucotis) were specialized substrate-restricted searchers, seeking invertebrate and carbohydrate foods among the exfoliating bark of Eucalyptus.
The search tactics of birds in this south temperate Australian forest were similar to those of birds in a north temperate forest in New Hampshire, USA, previously reported by Robinson and Holmes (1982). The differences in food-searching behavior between these phylogenetically distinct avifaunas (e.g. search flight and prey-attack flight lengths, hop/flight ratios, foraging rates) reflect the effects of unique foliage structures (e.g. spacing of branches, arrangements of leaves) and food resources at each site.
These findings support the hypothesis that habitat structure and food availability provide opportunities and constraints on how birds search for and capture food in forest habitats. These in turn are postulated to affect the success of particular bird species exploiting those habitats and thus influence bird community patterns.
Abundance and Habitat Selection of Two American Kestrel Subspecies in North-Central Florida
Authors: Bohall-Wood Petra , Collopy Michael W. 
Published: September 2019

Abstract
We censused American Kestrels (Falco sparverius) in the three vegetation communities representative of north-central Florida (pine flatwoods, sandhills, and agriculture/mixed hardwoods) along 24 16-km roadside transects. The winter kestrel population included resident F. s. paulus and migrant F. s. sparverius. Eighty-four percent of the 1,433 kestrels were sighted in winter, reflecting a significant influx of migrant F. s. sparverius, and were primarily females (65%). Significant (P < 0.05) sexual differences in winter habitat use were attributed to the large numbers of migrants. Males preferred closed habitats and smaller-sized open areas, and females preferred open habitats and larger open areas. Wintering kestrels were most abundant (P < 0.05) in the agriculture/mixed-hardwoods community (51%) and least abundant in the pine-flatwoods community (13%). Seventy-one percent of the 233 kestrels seen during summer were identified as F. s. paulus. Males and females were observed in approximately equal numbers and exhibited no differences in habitat preference. Falco s. paulus preferred the sandhill community (79%) to the agriculture/mixed hardwoods and pine flatwoods. Within the sandhill community, resident kestrels significantly increased their use of the pine/oak woodlands during summer.
Role of Sibling Aggression in Food Distribution to Nestling Cattle Egrets (Bubulcus Ibis)
Authors: Ploger Bonnie J. , Mock Douglas W. 
Published: September 2019

Abstract
Sibling aggression occurs in a wide variety of asynchronously hatching bird species. In some, fights among siblings lead inevitably to death, in which case the benefits of winning are clear. In species where sibling aggression is common but usually not fatal, the benefits gained by winning and the methods used to achieve them are less obvious. In a Texas colony of Cattle Egrets (Bubulcus ibis), sibling aggression was frequent but siblicide rare. Parents rarely interfered with fights. Last-hatched chicks lost more fights and received less food than their elder siblings. Fighting limited the losers' immediate access to food and contributed to the senior sib's ability to monopolize boluses. These results are consistent with the hypothesis that monopolizable food can act as both a proximate and ultimate cause of sibling aggression. The main effect of sibling aggression lay in depressing food supplies to last-hatched chicks. First- and second-hatched sibs accrued roughly equal feeding advantages.
Pairing Success of Kirtland's Warblers in Marginal vs. Suitable Habitat
Authors: Probst John R. , Hayes Jack P. 
Published: September 2019

Abstract
We compared pairing success of male Kirtland's Warblers (Dendroica kirtlandii) in different habitats to test the hypothesis that a lower proportion of males in marginal habitat are mated. Fewer than 60% of the males in marginal habitat were paired, but 95% of the males in suitable habitat were paired. We estimated the overall pairing success of the known breeding population at 85%. We could not estimate the number of females because the adult sex ratio is unknown, and an unknown proportion of Kirtland's Warblers are polygynous. The Kirtland's Warbler population was fairly constant from 1971 to 1983, despite markedly improved nest success resulting from cowbird control measures. If there are more males than females, or if many females fail to breed or must accept mated males or marginal habitat, population growth could be impeded. We combined reduced pairing success with an estimate of fledgling mortality, and revised the estimated number of fall immatures to between 369 and 471 birds-about 36% lower than the uncorrected estimate. Lower annual productivity of a static population implies higher annual survivorship of adults, yearlings, or both.
Increase of Parental Effort with Brood Size in a Nidifugous Bird
Authors: Schindler Martin , Lamprecht Jürg 
Published: September 2019

Abstract
Positive correlations of brood size with some parental activities [vigilance (in females), approaching young (in males and females), and attack (in males)] and a negative correlation of female feeding time with brood size were found in a sample of 23 semicaptive Bar-headed Goose (Anser indicus) families. Detailed examination of these correlations suggests that some components of parental care in geese represent "shared parental investment" (Lazarus and Inglis 1978, 1986). The benefits of parental care are divided among the offspring, so that in precocial birds, as in altricial birds, clutch size may be adapted to selection pressures that act after the young hatch.
Body and Organ Mass and Body Composition of Postbreeding Female Lesser Scaup
Authors: Austin Jane E. , Fredrickson Leigh H. 
Published: September 2019

Abstract
Changes in body and organ mass and body composition of postbreeding female Lesser Scaup (Aythya affinis) were investigated in the prairie-pothole region of southwestern Manitoba. Body mass was lowest during the wing molt and peaked during the migratory period. Most digestive organs gradually increased in mass through the postbreeding season. Lipid reserves remained relatively constant from the preflightless through the postflightless periods (x̄ = 43 g). The marked increase in lipids in the migratory period (x̄ = 183 g, P < 0.05) corresponded with premigratory hyperphagia. Time spent feeding explained 87% of the variation in lipid levels during the postbreeding season. Protein reserves declined with the onset of wing molt (P < 0.001) and increased during the postflightless period (P < 0.05). Breast muscle mass followed a similar pattern and was strongly correlated with molt intensity (r = 0.799, P < 0.001). Protein reserves, in particular the breast muscles, provide at least part of the protein required for feather production. Low body mass and lipid reserves during molt may not indicate energetic or nutritional stress but, alternatively, may be part of a postbreeding strategy to minimize energy demands and to reduce the length of the flightless period.
Cranial Kinesis in the Late Cretaceous Birds Hesperornis and Parahesperornis
Authors: Bühler Paul , Martin Larry D. , Witmer Lawrence M. 
Published: September 2019

Abstract
A recently discovered skull of the Cretaceous toothed diving bird Hesperornis permits evaluation of previous descriptions of the skull, analysis of cranial kinesis in hesperornithid birds, and discussion of the evolution of avian cranial kinesis. We found no evidence in hesperornithids for mesokinesis, a system that in lizards involves relative movement of the frontals and parietals. "Maxillokinesis," the fore-aft movements of the palato-maxillary arcade, was also rejected. Evidence for cranial kinesis in hesperornithid birds involves the presence of a streptostylic quadrate bone of virtually modern morphology, three types of flexion zones at the posterior end of the upper jaw, and a hiatus in the nasal-interorbital septum. Among the forms of kinesis found in modern birds, prokinesis, in which the upper jaw moves as a unit, was the dominant type of cranial kinesis in hesperornithids as indicated by the rigid construction of the upper jaw, the position of the holorhinal nostril, and the anteriorly truncate mesethmoid bone; rhynchokinesis and amphikinesis were not possible. Prokinesis is considered primitive for at least the group including Hesperornithiformes and later birds. Discovery of prokinesis in Hesperornis represents the first time all of the morphological correlated of prokinesis have been identified in a bird plesiomorphically lacking pterygoid segmentation.
Inter and Intraspecific Relationships between Egg Size and Clutch Size in Waterfowl
Authors: Rohwer Frank C. 
Published: September 2019

Abstract
Lack (1967, 1968a) proposed that clutch size of waterfowl and other birds with self-feeding young was limited by females' ability to produce eggs. Lack supported this egg-production hypothesis by showing a strong inverse relationship between egg size and clutch size within and among species of waterfowl. A reanalysis using updated data and more appropriate statistics failed to confirm Lack's results. Grouping all the waterfowl produced a weak (r2 = 0.13 inverse relationship between relative egg size and relative clutch size. This relationship was due mainly to a handful of ducks that nest on oceanic islands. Analyses by tribes showed that relative egg size and relative clutch size were inversely related in only 2 of the 8 major tribes of waterfowl. Finally, intraspecific analyses failed to reveal a trade-off between egg size and clutch size in Blue-winged Teal (Anas discors) and Northern Shovelers (A. clypeata). Similar intraspecific analyses for 12 other waterfowl have failed to show the predicted inverse relationship between egg size and clutch size. These results suggest that the widely accepted egg-production hypothesis may be considerably overemphasized.
The Scleral Ossicles of Opisthocomus and Their Phylogenetic Significance
Authors: Queiroz Kevin de , Good David A. 
Published: September 2019

Abstract
Dried scleral rings of Opisthocomus, Galliformes, Cuculiformes, and other birds were examined to determine the pattern of ossicle overlap in Opisthocomus and its bearing on the phylogenetic relationships of this taxon. Although Opisthocomus shares a derived number of 12 scleral ossicles with cuculid Cuculiformes, the pattern of ossicle overlap differs. Nevertheless, fewer modifications are required to derive the number and pattern of ossicles in Opisthocomus from the conditions in cuculid or musophagid Cuculiformes than from the conditions in any galliform. Our findings also indicate that the scleral rings of birds, unlike those of lizards, often do not conserve overlap relations between adjacent ossicles during phylogeny.
An Analysis of Function in the Formation Flight of Canada Geese
Authors: Badgerow John P. 
Published: September 2019

Abstract
I analyzed formations of Canada Geese (Branta canadensis) with a single, direct method of testing predictions from multiple hypotheses. The results support both energetic (aerodynamic) advantage and orientation communication through visual contact as functions of this complex behavior. Comparison of observed positioning patterns with criteria for optimal function suggests priority may be given to the maximization of energy savings within limits imposed by environmental and other constraints.
Activation of autophagy in early neonatal mice increases primordial follicle number and improves lifelong fertility†
Authors: Watanabe Ren , Sasaki Sho , Kimura Naoko 
Published: September 2019

Abstract
The number of stockpiled primordial follicles is thought to be responsible for the fate of female fertility and reproductive lifetime. We previously reported that starvation in nonsuckling early neonatal mice increases the number of primordial follicles with concomitant autophagy activation, suggesting that autophagy may accelerate the formation of primordial follicles. In this study, we attempted to upregulate the numbers of primordial follicles by administering an autophagy inducer and evaluated the progress of primordial follicle formation and their fertility during the life of the mice. To induce autophagy, mice were intraperitoneally injected with the Tat-beclin1 D-11 peptide (0.02 mg/g body weight) at 6–54 h or 60–84 h after birth. In animals that received Tat-beclin 1 D-11 by 54 h after birth, the primordial follicle numbers were significantly increased compared with the control group at 60 h. The ratio of expressed LC3-II/LC3-I proteins was also significantly greater. The numbers of littermates from pregnant females that had been treated with Tat-beclin 1 D-11 were maintained at remarkably greater levels until 10 months old. These results were supported by an abundance of primordial follicles at even 13–15 months old.
Protective effects of astaxanthin on lipopolysaccharide-induced inflammation in bovine endometrial epithelial cells†
Authors: Wan Fa-Chun , Zhang Chen , Jin Qing , Wei Chen , Zhao Hong-Bo , Zhang Xiang-Lun , You Wei , Liu Xiao-Mu , Liu Gui-Fen , Liu Yi-Fan , Tan Xiu-Wen 
Published: September 2019

Abstract
Astaxanthin (AST), a natural antioxidant carotenoid, has been shown to exert anti-inflammatory effects. However, to our knowledge, no study has specifically addressed the potential protective effects of AST against bovine endometritis. The purpose of this study was to examine whether treatment with AST could protect endometrial epithelial cells against lipopolysaccharide (LPS)-induced inflammatory injury. Treatment of bovine endometrial (BEND) epithelial cell line with AST reduced LPS-induced production of interleukin-6 and tumor necrosis factor-alpha, increased the cellular activity of superoxide dismutase and catalase, decreased the proportion of apoptotic cells, and promoted the production of insulin-like growth factor and epithelial growth factor. The effects of AST were mediated through the downregulation of B-cell lymphoma 2 (Bcl-2) associated X, apoptosis regulator (Bax), and cleaved caspase-3 and through the upregulation of Bcl-2. Moreover, AST significantly increased the expression of the tight junction proteins (TJP) claudin, cadherin-1, and TJP1, which play an essential role in the maintenance of host endometrial defense barrier against pathogen infection. Collectively, these results demonstrated that treatment with AST protected against oxidative stress, prevented cell apoptosis, promoted BEND cells viability, and increased the production of growth factors, in addition to activating the endometrial defense barrier. Therefore, AST is a promising therapeutic agent for the prevention and treatment of endometritis. This finding is of utmost importance in the present times when the excessive use of antibiotics has resulted in the development of antibiotic-resistant bacteria.
Past behavior and future judgements: seizing and freezing in response to cyber operations
Authors: Gomez Miguel Alberto 
Published: September 2019

Abstract
The use of cyber operations as a foreign policy instrument continues to stimulate academic interest towards interstate behavior in this domain. With continued investment in offensive cyber capabilities, there is an urgency to provide both academics and policy-makers with a better grasp of this phenomenon. While the past decade saw the growth of frameworks that highlight systemic and/or technological factors, this article investigates the role of pre-existing beliefs in the attribution of malicious cyber operations. Through survey experiments, it highlights the phenomenon of seizing and freezing with respect to attributive judgements in response to degradative cyber operations. With respect to theory, the results contribute to the emerging study of the cognitive–affective aspects of cyberspace. As for policy, the results illustrate the potential for biased judgements in response to incidents and reinforces the need to develop mechanisms that minimize its impact on state behavior.
Africa’s Voice in the Formation, Shaping and Redesign of International Investment Law
Authors: Mbengue Makane Moïse 
Published: September 2019

Abstract
Africa has often been presented as an ‘investment rules taker’, despite its longstanding contribution to the formation and shaping of the international investment regime. The present contribution seeks to analyze why Africa has been perceived as such and attempts to shed light on the active role that African countries have played since their independence in the development of the investment regime and also in the promotion of the ICSID system. The contribution also explores new avenues that are provided through the ‘Africanization’ of international investment law and their impact on the current redesign of the investment regime. It finally suggests options regarding the current negotiations of an Investment Protocol at the level of the African Union and ways to reinforce synergies between ICSID and the African Union.
Atomistic insight into the kinetic pathways for Watson–Crick to Hoogsteen transitions in DNA
Authors: Vreede Jocelyne , Pérez de Alba Ortíz Alberto , Bolhuis Peter G , Swenson David W H 
Published: September 2019

AbstractDNA predominantly contains Watson–Crick (WC) base pairs, but a non-negligible fraction of base pairs are in the Hoogsteen (HG) hydrogen bonding motif at any time. In HG, the purine is rotated ∼180° relative to the WC motif. The transitions between WC and HG may play a role in recognition and replication, but are difficult to investigate experimentally because they occur quickly, but only rarely. To gain insight into the mechanisms for this process, we performed transition path sampling simulations on a model nucleotide sequence in which an AT pair changes from WC to HG. This transition can occur in two ways, both starting with loss of hydrogen bonds in the base pair, followed by rotation around the glycosidic bond. In one route the adenine base converts from WC to HG geometry while remaining entirely within the double helix. The other route involves the adenine leaving the confines of the double helix and interacting with water. Our results indicate that this outside route is more probable. We used transition interface sampling to compute rate constants and relative free energies for the transitions between WC and HG. Our results agree with experiments, and provide highly detailed insights into the mechanisms of this important process.
VDJdb in 2019: database extension, new analysis infrastructure and a T-cell receptor motif compendium
Authors: Bagaev Dmitry V , Vroomans Renske M A , Samir Jerome , Stervbo Ulrik , Rius Cristina , Dolton Garry , Greenshields-Watson Alexander , Attaf Meriem , Egorov Evgeny S , Zvyagin Ivan V , Babel Nina , Cole David K , Godkin Andrew J , Sewell Andrew K , Kesmir Can , Chudakov Dmitriy M , Luciani Fabio , Shugay Mikhail 
Published: September 2019

Abstract
Here, we report an update of the VDJdb database with a substantial increase in the number of T-cell receptor (TCR) sequences and their cognate antigens. The update further provides a new database infrastructure featuring two additional analysis modes that facilitate database querying and real-world data analysis. The increased yield of TCR specificity identification methods and the overall increase in the number of studies in the field has allowed us to expand the database more than 5-fold. Furthermore, several new analysis methods are included. For example, batch annotation of TCR repertoire sequencing samples allows for annotating large datasets on-line. Using recently developed bioinformatic methods for TCR motif mining, we have built a reduced set of high-quality TCR motifs that can be used for both training TCR specificity predictors and matching against TCRs of interest. These additions enhance the versatility of the VDJdb in the task of exploring T-cell antigen specificities. The database is available at https://vdjdb.cdr3.net.
Aligned 3D porous polyurethane scaffolds for biological anisotropic tissue regeneration
Authors: Lin Weiwei , Lan Wanling , Wu Yingke , Zhao Daiguo , Wang Yanchao , He Xueling , Li Jiehua , Li Zhen , Luo Feng , Tan Hong , Fu Qiang 
Published: September 2019

Abstract
A green fabrication process (organic solvent-free) of artificial scaffolds is required in tissue engineering field. In this work, a series of aligned three-dimensional (3D) scaffolds are made from biodegradable waterborne polyurethane (PU) emulsion via directional freeze–drying method to ensure no organic byproducts. After optimizing the concentration of polymer in the emulsion and investigating different freezing temperatures, an aligned PUs scaffold (PU14) generated from 14 wt% polymer content and processed at −196°C was selected based on the desired oriented porous structure (pore size of 32.5 ± 9.3 μm, porosity of 92%) and balanced mechanical properties both in the horizontal direction (strength of 41.3 kPa, modulus of 72.3 kPa) and in the vertical direction (strength of 45.5 kPa, modulus of 139.3 kPa). The response of L929 cells and the regeneration of muscle tissue demonstrated that such pure material-based aligned 3D scaffold can facilitate the development of orientated cells and anisotropic tissue regeneration both in vitro and in vivo. Thus, these pure material-based scaffolds with ordered architecture have great potentials in tissue engineering for biological anisotropic tissue regeneration, such as muscle, nerve, spinal cord and so on.