Climate change is causing changes in weather patterns and has led to prolonged droughts. Much of western North America has experienced recent droughts, especially in California, which experienced a historic drought from 2012–2016. Drought can significantly impact aquatic turtles, especially those populations existing in ephemeral habitats. Much of the range of western pond turtles (Actinemys) has been subject to recent droughts. In 2017, after the worst of the drought had passed, I sampled a large population of Actinemys along the southern flank of the Tehachapi Mountains, California, which I first trapped in 2007 and 2010. I trapped the small pond in four of seven years between 2017 and 2023 when there was much less water than before. I caught only 15% (48/321) of the number of turtles I caught before the drought, but there were adult turtles that survived from earlier trapping, unmarked adults that were alive in 2010, young turtles, and many reproductive females. Growth rates were lower than previously, but growth rates were increasing in the last 2 years of trapping. Survivorship in 2017–2023 was similar to that in 2007/2010. Unlike many small ponds in the range of Actinemys that are ephemeral, relying on water input from the surrounding watershed, the study pond is spring-fed. Intermittent years of high rainfall (>500 mm) likely have recharged the surrounding aquifer that keep this pond with some water even in drought years, allowing the population of Actinemys at Gorman Pond to survive an extended drought period.
Photoperiod is a key environmental factor influencing the growth of crustaceans; however, its specific effects and underlying mechanisms on the early growth and molting of juvenile Macrobrachium rosenbergii remain poorly understood. In this study, we investigated the effects of different photoperiods on early growth, molting, and hepatopancreatic metabolism. The results showed that survival rate, weight gain rate, and specific growth rate were significantly higher in the L24:D0 group compared with the L12:D12 and L0:D24 groups. Furthermore, as the duration of light exposure increased, hemolymph levels of 20-hydroxyecdysone (20E) and crustacean hyperglycemic hormone (CHH) also increased significantly (P < 0.05). The expression levels of genes including CHH, ECR, HSP70, MIH, and KRLF were significantly higher in the L24:D0 group than in the other two groups (P < 0.05). Under this condition, 20E content showed a significant positive correlation with RXR and CAN expression levels. Non-targeted metabolomic analysis revealed differential enrichment of ABC transporters, nucleotide metabolism, and the FoxO signaling pathway among treatments. Lipid molecules such as phosphatidylcholine and phosphatidylethanolamine—key metabolites in the glycerophospholipid metabolic pathway—exhibited enhanced metabolism under long photoperiods. These metabolites interacted with one another while simultaneously participating in cellular autophagy, sugar metabolism, and other processes. Mantel test results indicated that juvenile shrimp growth performance and photoperiod were significantly positively correlated with phosphatidylinositol metabolite levels (P < 0.05). These findings provide a solid foundation for elucidating the photoperiod-regulated molting mechanism and for improving the management efficiency of factory-scale aquaculture of M. rosenbergii.
In this paper, we study the angle testing problem in the context of similarity search in high-dimensional Euclidean spaces and propose two projection-based probabilistic kernel functions, one designed for angle comparison and the other for angle thresholding. Unlike existing approaches that rely on random projection vectors drawn from Gaussian distributions, our approach leverages reference angles and adopts a deterministic structure for the projection vectors. Notably, our kernel functions do not require asymptotic assumptions, such as the number of projection vectors tending to infinity, and can be theoretically and experimentally shown to outperform Gaussian-distribution-based kernel functions. We apply the proposed kernel function to Approximate Nearest Neighbor Search (ANNS) and demonstrate that our approach achieves a 2.5x--3x higher query-per-second (QPS) throughput compared to the widely-used graph-based search algorithm HNSW.
We measure the projected angle on the plane of the sky between adjacent symmetry axes of tens of multipolar planetary nebulae and find that the distribution of these misalignment angles implies a random three-dimensional angle distribution limited to <60 degrees. We identify a symmetry axis as a line connecting two opposite lobes (bubbles) or clumps. We build a cumulative distribution function of the projected angles alpha and find that an entirely random distribution of the three-dimensional angles delta between adjacent symmetry axes, namely, uncorrelated directions, does not fit the observed one. A good fit to the observed distribution is a limited random distribution of the three-dimensional angle between adjacent symmetry axes, i.e., random distribution in the range of 20<delta<60 degrees. We assume that a pair of jets along the angular momentum axis of an accretion disk around the companion shape each symmetry axis. The limited random distribution might result from two sources of angular momentum to the accretion disks with comparable magnitude: one with a fixed direction and one with a stochastic direction variation. We discuss a scenario where the fixed-axis angular momentum source is the binary orbital angular momentum, while the stochastic source of angular momentum is due to the vigorous envelope convection of the mass-losing giant progenitor.
Long-chain polyunsaturated fatty acids (LC-PUFA) play key roles in sex steroid hormone synthesis in fish. Regarding docosahexaenoic acid (DHA), currently the regulating effects were mostly evaluated in female fish rather than males. This study aimed to investigate the DHA effects on the sex steroid hormone production in male Chinese tongue sole. Three experimental diets were prepared, containing different DHA levels: a control (C) group (5.16% DHA of total fatty acids [TFA]), a low DHA group (DHA-L, 8.93%), and a high DHA group (DHA-H, 16.47%). A 58-day feeding experiment was conducted, and each diet was fed to triplicate tanks of fish. Additionally, an in vitro study with Leydig’s cells of this species was conducted to validate the in vivo results. The concentration of testosterone (T) and 11-ketotestosterone (11-KT) in the serum increased with increasing levels of dietary DHA. Dietary DHA significantly upregulated the expression of steroid hormone biosynthetic genes p450c17, hsd17b1, hsd3b1, aromatase, hsd11b2, and p45011b in the testis. The protein expression of Hsd17b1 in the testis of the DHA-H group was significantly higher compared to the other two groups, while the expression level of P450c17 showed an increasing trend with increasing dietary DHA levels. However, the in vitro results confirmed that the final concentration of DHA at 50 μmol/L could significantly increase the gene expression of p450c17 in Leydig’s cells. In conclusion, dietary DHA may promote the synthesis of T and 11-KT through the regulation of protein (Hsd17b1 and P450c17) and gene (p450c17, hsd17b1, hsd3b1, aromatase, hsd11b2, and p45011b) expression of a series of key steroid hormone biosynthetic enzymes in male Chinese tongue sole.
Benjamín A. Itzá-Ortiz, Mónica Moreno Rocha, Víctor Nopal-Coello
In this work we introduce the broken line construction, which is a geometric and combinatorial algorithm that computes periodic Sturmian angles of a given period, yielding the locations of their landing parameters in the Mandelbrot set. An easy to implement method to compute the conjugated angle of a periodic Sturmian angle is also provided. Furthermore, if $θ$ is a periodic Sturmian angle computed by the broken line construction, then we show the existence of a one-to-one correspondence between its binary expansion and its associated kneading sequence.
Primordial non-Gaussianities (PNG) leave unique signatures in the bispectrum of the large-scale structure. With upcoming galaxy surveys set to improve PNG constraints by at least one order of magnitude, it is important to account for any potential contamination. In our work we show how to include wide-angle effects into the 3-dimensional observed galaxy bispectrum. We compute the leading wide-angle corrections to the monopole, finding that they could mimic local PNG with an amplitude of $f_{\rm NL} = \mathcal{O}\left( 0.1 \right)$. We also compute the dipole induced by wide-angle effects, whose amplitude is a few-percent of the flat-sky monopole. We estimate that wide-angle effects in the monopole can be safely neglected for survey volumes of the order of $8~\mathrm{Gpc}^3 h^{-3}$, while the dipole can start being detected from surveys probing volumes larger than $50~\mathrm{Gpc}^3 h^{-3}$. Our formalism can be readily adapted to realistic survey geometries and to include relativistic effects, which may become relevant at high redshifts.
هدف از این تحقیق بررسی اثر افزودن اسید لاکتیک به جیره غذایی قزل آلای رنگین کمان بر غلظت مواد معدنی و پروتئینهای پلاسمای خون ماهی بود. به این منظور 4 جیره غذایی حاوی 0، 5، 10 و 20 گرم اسید لاکتیک در کیلوگرم جیره به مدت 8 هفته به ماهی ها داده شدند (سه مخزن برای هر جیره) . نتایج نشان داد که افزودن اسید لاکتیک به جیره غذایی اثر معنی داری روی غلظت کلسیم، فسفر، آهن، مس، روی، پروتئین کل و گلبولین پلاسما داشت (P < 0.05). ولی ایمنوگلبولین کل و آلبومین پلاسما تحت تاثیر افزودن اسید لاکتیک به جیره غذایی نبودند (P > 0.05). همه غلظتهای اسید لاکتیک به طور معنی داری غلظت کلسیم پلاسما را افزایش دادند. فسفر پلاسما در تیمارهای 5 و 10 گرم اسید لاکتیک بالاتر از تیمار شاهد بودند. غلظت پلاسمایی آهن در تیمار 10 و 20 گرم اسید لاکتیک، مس در تیمار 20 گرم اسید لاکتیک و روی در تیمار 10 گرم اسید لاکتیک به طور معنی داری بالاتر از تیمار شاهد بودند. پروتئین کل و گلبولین پلاسما در تیمار 10 گرم اسید لاکتیک بالاتر از تیمار شاهد بودند. نتایج این تحقیق نشان میدهند که افزودن اسید لاکتیک به جیره غذایی قزل آلای رنگین کمان نقش موثری در افزایش غلظت مواد معدنی و پروتئینهای پلاسما دارد. بر این اساس، غلظت 20-10 گرم در کیلوگرم اسید لاکتیک بهترین نتایج را داشته اند.
We argue that in general renormalizable field theories the topological angles may develop an additive beta function starting no earlier than 2-loop order. The leading expression is uniquely determined by a single model-independent coefficient. The associated divergent diagrams are identified and a few independent methods for extracting the beta function in dimensional regularization are discussed. We show that the peculiar nature of the topological angles implies non-trivial constraints on the anomalous dimension of the CP-violating operators and discuss how a non-vanishing beta function affects the Weyl consistency conditions. Some phenomenological considerations are presented.
Stacked graphene multilayers with a small relative twist angle between each of the layers have been found to host flat bands at a series of magic angles. We consider the effect that Dirac point asymmetry between the layers, and in particular different Fermi velocities in each layer, may have on this phenomenon. Such asymmetry may be introduced by unequal Fermi velocity renormalizations through Coulomb interactions with a dielectric substrate. It also arises in an approximate way in tetralayer systems, in which the outer twist angles are large enough that there is a dominant moire periodicity from the stacking of the inner two layers. We find in such models that the flat band phenomenon persists in spite of this asymmetry, and that the magic angles acquire a degree of tunability through either controlling the screening in the bilayer system or the twist angles of the outer layers in the tetralayer system. Notably, we find in our models that the quantitative values of the magic angles are increased.
Adeleke Babatunde, Robertson‐Andersson Deborah, Moodley Gan
et al.
Abstract South Africa produces both marine and freshwater aquaculture species, with a combined production output of 5418 tons of food fish in 2015. Key aquaculture species reportedly cultured include four marine species – abalone, dusky kob, mussels and oysters and seven freshwater species – tilapia, trout, catfish, marron crayfish, carp, koi‐carp and ornamental species. The study aims to quantitatively assess the SWOT factors (Strengths, Weaknesses, Opportunities and Threats) of major aquaculture species of South Africa to determine their aquaculture development and market potential. Key food fish species – abalone, dusky kob, mussel, oyster, salmon, trout, tilapia, catfish and marron crayfish, were selected and subjected to qualitative and quantitative SWOT analyses by adapting the quantified SWOT analytical method coupled with the multi‐attribute decision‐making method MADM (SWOT‐MADM). Trout and tilapia are positioned in quadrant I, showing a combination of competitive strengths and market opportunities. Abalone, oyster and marron crayfish are situated in quadrant II; thus, they possess market opportunities but weak in competitive strengths as aquaculture species. Salmon and dusky kob are positioned in quadrant III; both species are weak in competitive strengths and faced with more threat factors rather than market opportunities. Mussel and catfish are in quadrant IV; both species thus have competitive strengths but are facing more threats than opportunities. Catfish recorded the highest competitive strengths due to internal assessment factors such as low FCR, ability to tolerate very high stocking density, rapid growth rate, high survival rate, hardiness and versatility of production systems and locations. Abalone and marron crayfish, on the other hand, both exhibited more market opportunities compared to other key aquaculture species due to external assessment factors like high pricing and good financial indicators. The study is expected to add to the existing body of knowledge and in guiding aquaculture industry stakeholders to make informed decisions with regards to the feasibility of aquaculture species in South Africa.
Close to a magical angle, twisted bilayer graphene (TBLG) systems exhibit isolated flat electronic bands and, accordingly, strong electron localization. TBLGs have hence been ideal platforms to explore superconductivity, correlated insulating states, magnetism, and quantized anomalous Hall states in reduced dimension. Below a threshold twist angle ($\sim$ $1.1^\circ$), the TBLG superlattice undergoes lattice reconstruction, leading to a periodic moiré structure which presents a marked atomic corrugation. Using a tight-binding framework, this research demonstrates that superlattice reconstruction affects significantly the electronic structure of small-angle TBLGs. The first magic angle at $\sim$ $1.1^\circ$ is found to be a critical case presenting globally maximized electron localization, thus separating reconstructed TBLGs into two classes with clearly distinct electronic properties. While low-energy Dirac fermions are still preserved at large twist angles $> 1.1 ^\circ$, small-angle ($\lesssim 1.1^\circ$) TBLG systems present common features such as large spatial variation and strong electron localization observed in unfavorable AA stacking regions. However, for small twist angles below $1.1 ^\circ$, the relative contribution of the local AA regions is progressively reduced, thus precluding the emergence of further magic angles, in very good agreement with existing experimental evidence.
Mackenzie A. Gunn, Peter J. Allen, Thomas Graham Rosser
et al.
Abstract Bolbophorus damnificus (Digenea: Bolbophoridae) causes significant losses in US catfish aquaculture. Little is known regarding the prevalence of infected snail hosts during outbreaks. To assess prevalence of snails observed shedding Bolbophorus spp. cercariae, as well as snails that were infected but not observed shedding cercariae, Planorbella trivolvis (n = 8,159) were collected from 14 catfish production ponds with B. damnificus activity in Mississippi, USA. Individual snails were placed in 10 ml of filtered (20 μm) reservoir pond water and observed for 48 hr for cercariae release. Identification of B. damnificus or Bolbophorus sp. type II cercariae was confirmed by duplex PCR. Genomic DNA was isolated from ~100 non‐shedding snails from each pond and the PCR assay used to identify the presence of B. damnificus or Bolbophorus sp. type II infected snails. The prevalence of snails shedding B. damnificus ranged from 0.23 to 13.6%. Observation of cercariae shedding underestimated true B. damnificus and Bolbophorus sp. type II prevalence in 42.9 and 64.3% of sampled ponds, respectively. Prevalence of B. damnificus infected snails was typically <3%, indicating numbers of infected snails during outbreaks are low and mitigation efforts may be successful simply by reducing snail numbers and not require complete eradication.
Parsha Shanjana Brishti, Kazi Sonia Sultana, Md. Jayedul Islam
et al.
The Sonadia Island, located at the south-east coast of Bangladesh, comprises a wide variety of wetland habitats including mudflats, sand dunes and mangroves which made this island a favoured habitat for diversified molluscan fauna. This paper deals with the new distributional record of two species of marine Bivalvia in Bangladesh- Tellinides timorensis Lamarck, 1818 and Vepricardium coronatum (Schröter, 1786) belonging to the family Tellinidae and Cardiidae respectively. Analysis of taxonomy, diagnosis of shell, geographic distribution and habitat, illustrations of each species and identification characteristics were presented in this paper.
Roberto Dvornicich, Francesco Veneziano, Umberto Zannier
This paper is concerned with configurations of points in a plane lattice which determine angles that are rational multiples of $π$. We shall study how many such angles may appear in a given lattice and in which positions, allowing the lattice to vary arbitrarily. This classification turns out to be much less simple than could be expected, leading even to parametrizations involving rational points on certain algebraic curves of positive genus.Bulletin of the American Mathematical Society
This paper develops a comprehensive framework of Area Angle Monitoring (AAM) to monitor the stress of bulk power transfer across an area of a power transmission system in real-time. Area angle is calculated from synchrophasor measurements to provide alert to system operators if the area angle exceeds pre-defined thresholds. This paper proposes general methods to identify these warning and emergency thresholds, and tests a mitigation strategy to relieve the area stress when the area angle exceeds the threshold. In order to handle the limited coverage of synchrophasor measurements, this paper proposes methods to estimate phase angles for boundary buses without synchrophasor measurements, which extends the application of AAM. AAM is verified for a power transmission area in the Western Electricity Coordinating Council system with both simulated data and synchrophasor measurements recorded from real events. A utility deployment to test the framework for monitoring area angle with live-stream and recorded synchrophasor data is described.