Hasil untuk "Natural history (General)"

Elana Resnick, Elana Resnick, Anders Lundkvist et al.

The Community Coordinated Modeling Center (CCMC) at NASA Goddard Space Flight Center has developed comprehensive resources and initiatives to support the Heliophysics Big Year (HBY) during the approach to solar maximum. This paper details the CCMC’s extensive outreach efforts from October 2023 through December 2024, engaging diverse audiences including the general public, educators, and scientific communities. Key activities included partnerships with the Intrepid Museum and American Museum of Natural History, educational presentations reaching over 1,000 physics educators, and specialized workshops for high school teachers. The paper also highlights significant technological enhancements to the CCMC’s visualization capabilities, specifically the improved Integrated Space Weather Analysis (ISWA) system with its global synchronization features and specialized layout options. Additionally, we discuss the collaborative development of OpenSpace, a versatile 3D visualization tool that integrates data from observations, simulations, and space missions to support public engagement through planetarium shows and educational initiatives. Through these combined efforts, the CCMC has established multiple pathways for audiences to engage with heliophysics research and better understand space weather phenomena during this period of heightened solar activity.

Jean‐Nicolas Pradervand, Florian Zellweger, Jérémy Gremion et al.

Human‐induced alterations in natural water flow have seriously impaired the integrity of riverine ecosystems. Nonetheless, even in human‐altered riverine and adjacent terrestrial habitats, there is considerable potential for the protection of rare species if management practices prioritize biodiversity conservation. However, the management of such areas often presents complex challenges. On the one hand, efforts to mitigate natural hazards frequently overshadow biodiversity conservation objectives. On the other hand, high‐resolution maps of forest structures are often lacking but could be very useful for spatial prioritization of conservation efforts, especially as vegetation structure can be directly managed through local restoration activities. Here, we used an airborne LiDAR‐derived vegetation structure along an 80 km stretch of the Rhône River (Valais, Switzerland) to assess the habitat characteristics that best explain the presence of a flagship species, the common nightingale Luscinia megarhynchos, a species that historically thrived along this river system but has experienced a drastic population decline over the past decades. Nightingales showed a preference for dense vegetation in the lower strata above ground (3–6 m), as opposed to an open and sparsely vegetated ground level (0–1 m). The preferred habitats were predominantly located within forested regions, as indicated by a preference for taller canopies. These findings align surprisingly well with prior field research on the species, demonstrating the capability of high‐resolution LiDAR to upscale locally derived habitat preferences across very large areas. Based on LiDAR outputs, we proposed management recommendations for the whole river. Such spatially detailed information furthers our understanding of local habitat preferences of endangered species, thus facilitating the formulation of conservation recommendations at the scale of entire populations.

Yunli Feng, Sunwei Li, Daoyi Chen et al.

In order to study the scale effect in wave-structure interactions and the role that structure-related parameters (tension T or bending stiffness EI) plays, riser model tests under regular waves were conducted using the model with multiple geometric scales (1:15, 1:12 and 1:9) in a wave basin. The riser model used is a novel structural design combing the outer polyvinyl chloride pipe with the core steel rod which could be simplified as a cantilever beam. Different initial tension T acting on the riser are tested by adjusting the slotted weight. The results show that the amplitude varies in a cubic fashion with the distance from the fixed end. In addition, the influence of the wave period and top tension T on the amplitude are investigated, which ultimately leads to a dimensionless number π1 = KCd·TL2/EI where KC is the classical Keulegan–Carpenter number (KC), EI shows the bending stiffness of the riser model and L gives the pipe length. With the KC number revised to take the distance from the fixed end into the calculation, this parameter provides a good measure in estimating the amplitudes of the riser vibrations induced by the waves.

Arketa Pllumi Guli, Zamira Shabani, Emiljano Pjetri

Introduction: Dextrocardia is rare in the general population and may be associated with significant additional cardiac malformations. It is commonly associated with additional cardiac malformations. In this report, we have described the follow-up of a patient with Situs inversus dextrocardia and cyanogen complex cardiopathy in a 16-year-old Albanian male. The male patient born on 2007 in Albania, was referred to our ambulatory at 6 months of life by pediatrician cause of cyanosis and cardiac murmur. It was performed the echo Color Doppler examination, with the conclusion: situs inversus dextrocardia, unique ventricle, pulmonary arterial atresia. On 2008, a diagnostic catheterization was performed. The medico-chirurgical consultation has decided to leave the boy in natural history with a periodic follow–up. On 06.2009 in one of the routine examinations, there was make evidence of hypertrophy of the unique ventricle associated with arteria hypertension. From that time the patient is under medical treatment with periodic monitoring. Conclusions: The regular follow up of complex cyanogen congenital heart disease improve health care towards risqué target group. In heave desaturations patient the hypertension must be valuated as secondary complication of primary problem.   

Manuel Melgosa, Javier Hernández-Andrés, Manuel Sánchez-Marañón et al.

We analyzed the main colorimetric characteristics of lights on Mars’ surface from 3139 total spectral irradiances provided by the COMIMART model (J. Space Weather Space Clim. 5, A33, 2015), modifying the parameters of ‘solar zenith angle’ and ‘opacity’, related to the time of day and the amount of dust in the atmosphere of Mars, respectively. Lights on Mars’ surface have chromaticities that are mainly located below the Planckian locus, correlated color temperature in the range of 2333 K–5868 K, and CIE 2017 color fidelity indices above 93. For the 24 samples in the X-Rite ColorChecker^® and an extreme dust opacity change from 0.1 to 8.1 in the atmosphere, the average color inconstancy generated by the change in Mars’ light using the chromatic adaptation transform CIECAT16 was about 5 and 8 CIELAB units for solar zenith angles of 0° and 72°, respectively. We propose a method to compute total spectral irradiances on the surface of Mars from a selected value of correlated color temperature in the range of 2333 K–5868 K. This method is analogous to the one currently adopted by the International Commission on Illumination to compute daylight illuminants on the surface of Earth (CIE 015:2018, clause 4.1.2). The average accuracy of 3139 reconstructed total spectral irradiances using the proposed method was 0.9999558 using GFC (J. Opt. Soc. Am. A 14, 1007–1014, 1997) and 0.0009 Δ<i>E</i>_u^′v^′ units, a value just below noticeable chromaticity differences perceptible by human observers at 50% probability. Total spectral irradiances proposed by Barnes for five correlated temperatures agreed with those obtained from the current proposed method: on the average, GFC = 0.9979521 and 0.0023 Δ<i>E</i>_^′v^′ units.

Kristian Ions, Khan Ozdemir, Douglas Pender et al.

Gravel barrier beaches can offer natural protection to coastlines from adverse storm conditions. Understanding the morphodynamics of gravel barrier beaches is vital for the effective and sustainable management of these systems. Here, we use a synthetic dataset to investigate the morphodynamic response of the gravel barrier beach at Hurst Castle Spit, located on the Southwest coast of the United Kingdom, to both unimodal and bimodal storms. This spit is exposed to wind and swell waves propagating up the English Channel from the Southwest approaches and has suffered repeated storm erosion. The results are analyzed to identify the key drivers that govern the spatio-temporal gravel barrier morphodynamic responses to storms and to explore the morphodynamic states of the barrier. We found that the morphodynamic response of the barrier beach is strongly influenced by the combination of storm wave height and still water level. Further, the presence of swell waves can be a controlling factor in the barrier response.

Tao Liu, Xiaofei Shang, Yuanyuan Su et al.

[Objective] Green utilization efficiency of cultivated land in the lower Yellow River and its convergence and influencing factors were analyzed in order to provide a reference for ecological protection and high-quality development of cultivated land in the lower Yellow River. [Methods] Undesirable outputs such as surface pollution and carbon emissions from cultivated land, and the carbon sequestration and sink capacity of cultivated land resources were simultaneously incorporated into the evaluation index system. The green utilization efficiency, convergence, and influencing factors of cultivated land in 34 municipalities in the lower Yellow River from 2007 to 2020 were systematically analyzed using the EBM model, the convergence model, and the panel random effects Tobit model. [Results] ① The green utilization efficiency of cultivated land in the lower Yellow River showed an overall upward trend, but still did not reach the optimal state by the end of 2020. The green utilization efficiency of cultivated land in the lower Yellow River was spatially unbalanced. The green utilization efficiency of cultivated land in Southern He’nan and Northern Shandong provinces was high, while that in Zhengzhou, Weihai, and other cities was always low. ② From the perspective of efficiency decomposition, the main driving force for the improvement of green utilization efficiency of cultivated land in the lower Yellow River was scale efficiency, while the resistance came from pure technical efficiency. ③ From the convergence test, both σ convergence and β convergence existed in the green utilization efficiency of farmland in the lower Yellow River. The inter-city gap of cultivated land green utilization efficiency in He’nan Province was obviously lower than in Shandong Province, but the convergence rate in Shandong Province was faster. ④ In terms of influencing factors, crop planting structure and government financial support to agriculture increased green utilization efficiency of cultivated land in the lower Yellow River, while the urban-rural income gap, economic development level, and farmland machinery input intensity decreased green utilization efficiency. [Conclusion] In the future, the lower Yellow River should not only improve the comprehensive management level of the green utilization of cultivatedpland and strengthen inter-city exchanges and cooperation, but should also focus on the coordination between the convergence rate of green utilization efficiency of cultivated land and the development gap in each region while promoting development of the green utilization of cultivated land.

Roger Hart

A lifelong reproductive health plan is recommended for women with PCOS, with a focus on preconception risk factors including prevention of weight gain and optimisation of fertility. Metabolic risk factors, diabetes, cardiovascular disease, and sleep disorders are all increased in PCOS and screening and management is recommended. PCOS should be considered a high-risk condition in pregnancy with women identified and monitored. An increased premenopausal risk of endometrial cancer should be recognised. Depressive and anxiety symptoms are significantly increased and should be screened for in all women with PCOS, with psychological assessment and therapy as indicated. Shared decision making, self-empowerment and integrated models of care should be developed, funded, and evaluated. Supported healthy lifestyle remains vital throughout the lifespan in PCOS, with a strong focus on overall health, prevention of weight gain and if required on weight management. Combined oral contraceptive pills are first line pharmacological treatment for menstrual irregularity and hyperandrogenism, with no specific recommended preparation, and a preference for lower dose preparations and those with less side-effects. Metformin is recommended primarily for metabolic, although it is not routinely recommended for use in pregnant women with PCOS.

Martin Jakobsson, Larry A. Mayer

The ocean and the marine parts of the cryosphere interact directly with, and are affected by, the seafloor and its primary properties of depth (bathymetry) and shape (morphology) in many ways. Bottom currents are largely constrained by undersea terrain with consequences for both regional and global heat transport. Deep ocean mixing is controlled by seafloor roughness, and the bathymetry directly influences where marine outlet glaciers are susceptible to the inflow relatively warm subsurface waters - an issue of great importance for ice-sheet discharge, i.e., the loss of mass from calving and undersea melting. Mass loss from glaciers and the Greenland and Antarctic ice sheets, is among the primary drivers of global sea-level rise, together now contributing more to sea-level rise than the thermal expansion of the ocean. Recent research suggests that the upper bounds of predicted sea-level rise by the year 2100 under the scenarios presented in IPCC’s Special Report on the Ocean and Cryosphere in a Changing Climate (SROCCC) likely are conservative because of the many unknowns regarding ice dynamics. In this paper we highlight the poorly mapped seafloor in the Polar regions as a critical knowledge gap that needs to be filled to move marine cryosphere science forward and produce improved understanding of the factors impacting ice-discharge and, with that, improved predictions of, among other things, global sea-level. We analyze the bathymetric data coverage in the Arctic Ocean specifically and use the results to discuss challenges that must be overcome to map the most remotely located areas in the Polar regions in general.

Albertina Dias, Albertina Dias, Siby Kurian et al.

Colored dissolved organic matter (CDOM) is one of the important fractions of dissolved organic matter (DOM) that controls the availability of light in water and plays a crucial role in the cycling of carbon. High CDOM absorption in the Mandovi Estuary (Goa) during spring inter-monsoon (SIM) is largely driven by both in-situ production and anthropogenic activities. Here we have presented the CDOM variation in the estuary during SIM of 2014–2018 and compared it with that of 2020 when the COVID-19 outbreak imposed lockdown was implemented. During 2020, low CDOM absorption was observed at the mid-stream of the estuary as compared to the previous years, which could be attributed to low autochthonous production and less input from anthropogenic activities. On the other hand, high CDOM observed at the mouth during 2020 is linked to autochthonous production, as seen from the high concentrations of chlorophyll a. High CDOM in the upstream region could be due to both autochthonous production and terrestrially derived organic matter. Sentinel-2 satellite data was also used to look at the variations of CDOM in the study region which is consistent with in-situ observations. Apart from this, the concentration of nutrients (NO3–, NH4+, and SiO44–) in 2020 was also low compared to the previous reports. Hence, our study clearly showed the impact of anthropogenic activities on CDOM build-up and nutrients, as the COVID-19 imposed lockdown drastically controlled such activities in the estuary.

Jingyan Zhang, Jingyan Zhang, Mengqian Zhang et al.

Ammonia is a common environmental stressor encountered during aquaculture, and is a significant concern due to its adverse biological effects on vertebrate and invertebrate including crustaceans. However, little information is available on physiological and molecular responses in crustaceans under long-term ammonia exposure, which often occurs in aquaculture practices. Here, we investigated temporal physiological and molecular responses in the gills, the main ammonia excretion organ, of the swimming crab Portunus trituberculatus following long-term (4 weeks) exposure to three different ammonia nitrogen concentrations (2, 4, and 8 mg l–1), in comparison to seawater (ammonia nitrogen below 0.03 mg l–1). The results revealed that after ammonia stress, the ammonia excretion and detoxification pathways were initially up-regulated. These processes appear compromised as the exposure duration extended, leading to accumulation of hemolymph ammonia, which coincided with the reduction of adenosine 5′-triphosphate (ATP) and adenylate energy charge (AEC). Considering that ammonia excretion and detoxification are highly energy-consuming, the depression of these pathways are, at least partly, associated with disruption of energy homeostasis in gills after prolonged ammonia exposure. Furthermore, our results indicated that long-term ammonia exposure can impair the antioxidant defense and result in increased lipid peroxidation, as well as induce endoplasmic reticulum stress, which in turn lead to apoptosis through p53-bax pathway in gills of the swimming crab. The findings of the present study further our understanding of adverse effects and underlying mechanisms of long-term ammonia in decapods, and provide valuable information for aquaculture management of P. trituberculatus.

Christos Latsos, Jasper van Houcke, Klaas R. Timmermans et al.

The microalgae Rhodomonas sp. is known as an excellent feed source for live feed organisms such as copepods. The main benefits of feeding Rhodomonas to live feed animals are attributed to the relative high polyunsaturated fatty acid (PUFA) level, the combination of containing both docosahexaenoic acid (DHA) and eicosapentaenoic acid (EPA), and the ratio between these fatty acids (FA). It has been shown that microalgae are able to accumulate valuable metabolites, such as lipids, under adverse conditions. The easiest and most inexpensive method to induce stress to microalgae is through nitrogen (N) starvation. In this study, the effect of N-starvation on biomass concentration, cell volume, and cellular composition, such as fatty acid concentration and composition, and phycoerythrin (PE) concentration of Rhodomonas sp. during a period of 8 days, was investigated. The research was divided into two stages. In the first (growth) stage, Rhodomonas sp. was cultivated in small 400 ml photobioreactors (Algaemist-S) under optimal conditions in turbidostat mode, which reached a biomass concentration of 1.5 gDW L–1 and dilution rate of 1.3 d–1. Samples were taken every 24 h for cell density and volume and productivity measurements in order to ensure a healthy and stable culture. In the next stage (N-starvation), the biomass was washed and transferred in a reactor filled with N-depleted medium. During N-starvation, samples were taken for biomass concentration, cell volume, PE and FA composition. The results of this study demonstrate that the lipid content increased significantly from 9% (t = 0 h) to 30% (t = 120 h) of the dry weight. After 120 h of N-starvation, the total FA content of Rhodomonas sp. remained stable for the remainder of the experiment (next 72 h). The highest increase of the FA concentration was represented by C16:0, C:18:1, C18:2, and C18:3, with highest concentrations after 120 h of starvation. The maximum EPA and DHA concentrations were observed after 48 h of starvation, while the maximum DHA to EPA ratio was detected at the end of the starvation.

Steven G. Wilson, Georgina Hockings, Jo-Anne M. Deretic et al.

All members of the family Rhinocerotidae have the need to wallow in mud or water to protect their skin from sun damage, remove ectoparasites and for thermoregulation purposes. Just 72 wild Javan rhino (Rhinoceros sondaicus) remain on the planet, all located in their last stronghold in Ujung Kulon National Park (UKNP), West Java, Indonesia. Javan rhinos need to wallow regularly throughout the year, yet the role wallows play in their behaviour and the importance to the species remains little understood. In this study, we identified, mapped and studied 35 wallows in eastern UKNP, where rhinos were active. We spatially mapped and recorded each wallow’s characteristics. We examined rhino wallowing behaviour using 392 remote camera trap videos, taken across UKNP during a five-year study from 2011 to 2016. We identified and categorised eight behavioural patterns at and near wallows related to rhino daily activities and found that wallows have several key features for the Javan rhinos. Findings revealed that Javan rhinos, who construct the wallows themselves, choose sites with 75% shade cover and often at an elevation. Analysis of the rhino calls from camera trap videos taken at and near wallows, identify seven vocalisation descriptors with accompanying sonograms, a first for this rare and shy rainforest species. We discovered that Javan rhino utilise wallows not only for thermoregulatory function, but also as sites of interaction and communication. This has important implications for conservation and potential translocation of rhinos, which will require finding sites with suitability for the construction of wallows. Tous les membres de la famille des rhinocérotidés ont besoin de se vautrer dans la boue ou l'eau pour protéger leur peau des dommages du soleil, éliminer les ectoparasites et à des fins de thermorégulation. Il ne reste que 72 rhinocéros de Java (Rhinoceros sondaicus) sauvages sur la planète, tous situés dans leur dernier bastion du parc national d'Ujung Kulon (UKNP), à West Java, en Indonésie. Les rhinocéros de Java doivent se vautrer régulièrement tout au long de l'année, cependant le rôle des mares boueuses dans leur comportement et leur importance pour l'espèce restent peu compris. Dans cette étude, nous avons identifié, cartographié et étudié 35 mares boueuses dans l'est de l’UKNP, où les rhinocéros étaient actifs. Nous avons cartographié spatialement et enregistré les caractéristiques de chaque mare. Nous avons examiné le comportement des rhinocéros se vautrant dans la boue en utilisant 392 vidéos de pièges photographiques à déclenchement à distance, vidéos prises sur l’ensemble de l'UKNP au cours d'une étude de cinq ans de 2011 à 2016. Nous avons identifié et catégorisé huit modèles de comportements à proximité de et aux mares boueuses liées aux activités quotidiennes des rhinocéros et nous avons constaté que les mares boueuses ont plusieurs caractéristiques clés pour les rhinocéros de Java. Les résultats ont révélé que les rhinocéros de Java, qui construisent eux-mêmes les mares, choisissent des sites à 75% d'ombre et souvent en altitude. L’analyse des appels vocaux enregistrés dans les vidéos prises à l’aide de pièges photographiques à proximité de et aux mares boueuses, identifie sept descripteurs de vocalisation accompagnés de leurs sonogrammes, une première pour cette espèce rare et timide habitant en forêt tropicale. Nous avons découvert que le rhinocéros de Java utilise les mares non seulement pour leur fonction thermorégulatrice, mais aussi comme sites d'interaction et de communication. Cela a des implications importantes pour la conservation et le transfert potentiel des rhinocéros, et nécessitera de trouver des sites convenant à la construction de mares boueuses.

Kerry-Ann van der Walt, Ernst R. Swartz, Darragh J. Woodford et al.

No abstract available.

Kristy eWallmo, Daniel K Lew, Daniel K Lew

Non-market valuation allows society to express their preferences for goods and services whose economic value is not reflected in traditional markets. One issue that arises in applying non-market values in policy settings is defining the extent of the economic jurisdiction – the area that includes all people who hold values – for a good or service. In this paper we estimate non-market values for recovering eight threatened and endangered marine species in the US for two geographically embedded samples: households on the west coast of the US and households throughout the nation. We statistically compare species values between the two samples to help determine the extent of and variation in the economic jurisdiction for endangered species recovery. Our findings offer support to the tenet that the summation of non-market values across the country is appropriate when evaluating alternative policies for endangered species recovery.

David B Lowry, John H Willis

The role of chromosomal inversions in adaptation and speciation is controversial. Historically, inversions were thought to contribute to these processes either by directly causing hybrid sterility or by facilitating the maintenance of co-adapted gene complexes. Because inversions suppress recombination when heterozygous, a recently proposed local adaptation mechanism predicts that they will spread if they capture alleles at multiple loci involved in divergent adaptation to contrasting environments. Many empirical studies have found inversion polymorphisms linked to putatively adaptive phenotypes or distributed along environmental clines. However, direct involvement of an inversion in local adaptation and consequent ecological reproductive isolation has not to our knowledge been demonstrated in nature. In this study, we discovered that a chromosomal inversion polymorphism is geographically widespread, and we test the extent to which it contributes to adaptation and reproductive isolation under natural field conditions. Replicated crosses between the prezygotically reproductively isolated annual and perennial ecotypes of the yellow monkeyflower, Mimulus guttatus, revealed that alternative chromosomal inversion arrangements are associated with life-history divergence over thousands of kilometers across North America. The inversion polymorphism affected adaptive flowering time divergence and other morphological traits in all replicated crosses between four pairs of annual and perennial populations. To determine if the inversion contributes to adaptation and reproductive isolation in natural populations, we conducted a novel reciprocal transplant experiment involving outbred lines, where alternative arrangements of the inversion were reciprocally introgressed into the genetic backgrounds of each ecotype. Our results demonstrate for the first time in nature the contribution of an inversion to adaptation, an annual/perennial life-history shift, and multiple reproductive isolating barriers. These results are consistent with the local adaptation mechanism being responsible for the distribution of the two inversion arrangements across the geographic range of M. guttatus and that locally adaptive inversion effects contribute directly to reproductive isolation. Such a mechanism may be partially responsible for the observation that closely related species often differ by multiple chromosomal rearrangements.

M. Singh, W. Kaumanns, M. Singh et al.

The Lion-tailed Macaque (Macaca silenus) is a threatened species inhabiting the rainforests of the Western Ghats mountain range in southern India. Once assessed to be less than a thousand individuals remaining in the wild habitats, the population is now estimated to be between 3000 and 3500 individuals. However, the rainforest habitats of the species are highly fragmented. During the past three decades or less, the population of this species has severely declined due to habitat degradation and illegal hunting in several areas of its occurrence. In situ conservation programs included notification of certain areas as Lion-tailed Macaque conservation regions. Several captive breeding programs have been initiated in order to have a viable captive population of the species. However, the analysis reveals that both in situ and ex situ conservation programs have not achieved the desired success and the species is even more endangered than it was a few decades ago. In this article, we discuss these conservation programs and suggest further measures for effective conservation of Lion-tailed Macaques.

George B. Schaller

Ph.D., U. De V. Pienaar

The large mammals of the Kruger National Park - Their distribution and present-day status

Yirmed Demeke, Bekele Afework

A dung count survey plus ground observation of elephant in Mago NP during June 1997 to April 1998 estimated the population to be between 387 and 575. The maximum number of animals counted from a total of seven sights was 182. They occupy semi-arid bush and riverine valleys. During the past century elephants have become somewhat restricted in their range. They use to inhabit areas near Jinka town, Woito valley, Hamer, areas around Omorate and a large part of Tama Wildlife Reserve. However people coming from the central and northern parts of the country heavily exploited the populations. Data on movement suggest that some elephant may move south travelling up to 43 kms outside the park boundary. Calculated home ranges average 1597 sq kms. During the study period 26 elephants were known to have been killed for ivory. Both poaching and habitat destruction are threats to maintaining a elephant population in the Park.