Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 48
Filtrar
1.
Phys Chem Chem Phys ; 26(20): 14514-14528, 2024 May 22.
Artigo em Inglês | MEDLINE | ID: mdl-38629346

RESUMO

Several years ago the discovery of a conical intersection offered an explanation for the ultafast photodissociation of pyrrole. Subsequently, the photodissociation of pyrrole ammonia complexes PyH*(NH3)n with n ≥ 3 was studied in the gas phase as a model for a hydrogen-bond forming solvent. Two alternative mechanisms, electron coupled proton transfer (ECPT) and hydrogen atom transfer (HAT, also called the impulsive model, IM), have been proposed. The parent 1 : 1 complex was never studied, due to the short lifetime of the NH4 radical fragment. Here we report experiments on the deuterated species PyD*(ND3)n, including the 1 : 1 complex (n = 1). The velocity distribution of the ND4 radical is well approximated by a Maxwell-Boltzmann distribution of T ≈ 530 K, with a negative anisotropy parameter of ß = -0.3. The impulsive model predicts a much narrower velocity distribution with larger negative anisotropy. The ECPT model predicts a long lived intermediate that should allow thermal equilibration of the vibrational energy but should also destroy the rotational memory of the initially excited state. The average kinetic energy agrees with the prediction of the impulsive model, whereas the wide range of kinetic energies is more in line with ECPT. Hence the mechanism seems to be more complex and requires further theoretical modelling.

2.
J Water Health ; 20(2): 314-328, 2022 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-36366989

RESUMO

Wastewater-based epidemiology (WBE) is an effective approach for tracking information on spatial distribution and temporal trends of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) at the community level. Herein, the development, implementation, and operation of the wastewater monitoring program serving Tyrol - a federal province of Austria - are described. The development of this program was initiated by Tyrolean health authorities at the end of the first phase of the Coronavirus disease 2019 (COVID-19) pandemic (May 2020). In close co-operation with the water sector and academic institutions, efficient and effective workflows and processes for wastewater surveillance were established. The monitoring program went into operation in November 2020. By the end of July 2021, a total of 5,270 wastewater influent samples collected at 43 sites were analyzed. The monitoring program provided valuable insights into the development of the pandemic situation in Tyrol and fulfilled several tasks that are of importance in different phases of the pandemic. It represented an early-warning system, provided independent confirmation of temporal trends in COVID-19 prevalence, enabled the assessment of the effectiveness of measures, alerted about bursts of disease activity, and provided evidence for the absence of COVID-19. These findings underline the importance of establishing national wastewater monitoring programs as a complementary source of information for efficient and effective pandemic management.


Assuntos
COVID-19 , SARS-CoV-2 , Humanos , Águas Residuárias , COVID-19/epidemiologia , Vigilância Epidemiológica Baseada em Águas Residuárias , Áustria/epidemiologia
3.
Eur J Clin Microbiol Infect Dis ; 40(7): 1441-1449, 2021 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-33547522

RESUMO

Bloodstream infections (BSIs) require an accurate and fast identification of causative pathogens. Molecular diagnostics, in particular polymerase chain reaction (PCR)-based approaches for BSI diagnostics directly from whole blood, suffer from limitations such as inhibition leading to invalid results. In this retrospective study, we analyzed 23 parameters for their potential interference with LightCycler SeptiFast PCR tests (n = 2167) routinely performed at our institution. The overall inhibition rate was 9.1%. Test date, type of ward, procalcitonin levels, high leukocyte counts, and absolute neutrophil count were significantly associated with inhibition. For a subset (n = 448), cut-off values for leukocyte counts of < 5700 cells/µL and ≥ 26,900 cells/µL were significantly associated with a low (5%) and high (67%) inhibition risk. For patients with a moderate to high leukocyte count (5700-26,900 cells/µL), the additional administration of hydrocortisone significantly increased the inhibition risk. Furthermore, freezing of blood samples prior to DNA extraction and SF testing appeared to neutralize inhibitory factors. It remains to be investigated whether other molecular diagnostic tests are susceptible to similar inhibiting parameters.


Assuntos
Hidrocortisona/administração & dosagem , Técnicas de Diagnóstico Molecular/métodos , Reação em Cadeia da Polimerase/métodos , Sepse/microbiologia , Adolescente , Adulto , Idoso , Hemocultura/métodos , Criança , Pré-Escolar , Feminino , Humanos , Lactente , Recém-Nascido , Contagem de Leucócitos , Masculino , Pessoa de Meia-Idade , Reação em Cadeia da Polimerase Multiplex , Estudos Retrospectivos , Sensibilidade e Especificidade , Adulto Jovem
4.
Cell Microbiol ; 21(5): e13000, 2019 05.
Artigo em Inglês | MEDLINE | ID: mdl-30578712

RESUMO

Hemolytic uremic syndrome (eHUS) is a severe complication of human infections with Shiga toxins (Stxs)-producing Escherichia coli. A key step in the pathogenesis of eHUS is the interaction of Stxs with blood components before the targeting of renal endothelial cells. Here, we show that a single proteolytic cleavage in the Stx2a A-subunit, resulting into two fragments (A1 and A2) linked by a disulfide bridge (cleaved Stx2a), dictates different binding abilities. Uncleaved Stx2a was confirmed to bind to human neutrophils and to trigger leukocyte/platelet aggregate formation, whereas cleaved Stx2a was ineffective. Conversely, binding of complement factor H was confirmed for cleaved Stx2a and not for uncleaved Stx2a. It is worth noting that uncleaved and cleaved Stx2a showed no differences in cytotoxicity for Vero cells or Raji cells, structural conformation, and contaminating endotoxin. These results have been obtained by comparing two Stx2a batches, purified in different laboratories by using different protocols, termed Stx2a(cl; cleaved toxin, Innsbruck) and Stx2a(uncl; uncleaved toxin, Bologna). Stx2a(uncl) behaved as Stx2a(cl) after mild trypsin treatment. In this light, previous controversial results obtained with purified Stx2a has to be critically re-evaluated; furthermore, characterisation of the structure of circulating Stx2a is mandatory to understand eHUS-pathogenesis and to develop therapeutic approaches.


Assuntos
Escherichia coli/química , Toxina Shiga II/química , Toxina Shiga II/metabolismo , Animais , Plaquetas/efeitos dos fármacos , Plaquetas/metabolismo , Chlorocebus aethiops , Dicroísmo Circular , Fator H do Complemento/metabolismo , Escherichia coli/genética , Escherichia coli/metabolismo , Fluorescência , Humanos , Leucócitos/efeitos dos fármacos , Leucócitos/metabolismo , Neutrófilos/efeitos dos fármacos , Neutrófilos/metabolismo , Ligação Proteica , Conformação Proteica , Toxina Shiga II/genética , Triexosilceramidas/metabolismo , Tripsina , Células Vero
5.
Proc Natl Acad Sci U S A ; 111(15): 5741-6, 2014 Apr 15.
Artigo em Inglês | MEDLINE | ID: mdl-24706923

RESUMO

The plant hormone abscisic acid (ABA) acts both as a developmental signal and as an integrator of environmental cues such as drought and cold. ABA perception recruits an ABA-binding regulatory component [regulatory component of ABA receptor (RCAR)/PYR1/PYL] and an associated protein phosphatase 2C (PP2C). Phytohormone binding inactivates the phosphatase activity of the coreceptor, permitting phosphorelay of the ABA signal via downstream protein kinases. RCARs and PP2C coreceptors are represented by small protein families comprising 14 and 9 members in Arabidopsis, respectively. The specificity of the RCAR-PP2C interaction and the constraints contributing to specific combinations are poorly understood. In this contribution, we analyzed RCAR7/PYL13, which is characterized by three variant amino acid residues in the conserved ABA-binding pocket. RCAR7 regulated the phosphatase activity of the PP2Cs ABI1, ABI2, and PP2CA in vitro at nanomolar ABA levels; however, it was unable to regulate the structurally related hypersensitive to ABA 1 (HAB1). Site-directed mutagenesis of HAB1 established ABA-dependent regulation by RCAR7. Conversion of the noncanonical amino acid residues of RCAR7 into the consensus ABA-binding pocket did not perceptibly change receptor function. Ectopic expression of RCAR7 in Arabidopsis resulted in ABA hypersensitivity affecting gene regulation, seed germination, and stomatal closure. The RCAR7 loss-of-function mutant revealed no changes in ABA responses, similar to the RCAR9 knockout line, whereas the combined deficiency of RCAR7 and RCAR9 resulted in ABA-insensitive seed germination. The study shows a role of RCAR7 in early plant development, proves its ABA receptor function, and identifies structural constraints of RCAR7-PP2C interaction.


Assuntos
Ácido Abscísico/metabolismo , Proteínas de Arabidopsis/metabolismo , Arabidopsis/genética , Regulação da Expressão Gênica de Plantas/fisiologia , Fosfoproteínas Fosfatases/metabolismo , Reguladores de Crescimento de Plantas/metabolismo , Proteínas de Arabidopsis/genética , Primers do DNA/genética , Escherichia coli , Mutagênese Sítio-Dirigida , Fosfoproteínas Fosfatases/genética , Protoplastos/metabolismo , Reação em Cadeia da Polimerase Via Transcriptase Reversa
6.
Ecotoxicology ; 25(9): 1648-1665, 2016 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-27644949

RESUMO

Possible effects of clothianidin seed-treated oilseed rape on honey bee colonies were investigated in a large-scale monitoring project in Northern Germany, where oilseed rape usually comprises 25-33 % of the arable land. For both reference and test sites, six study locations were selected and eight honey bee hives were placed at each location. At each site, three locations were directly adjacent to oilseed rape fields and three locations were situated 400 m away from the nearest oilseed rape field. Thus, 96 hives were exposed to fully flowering oilseed rape crops. Colony sizes and weights, the amount of honey harvested, and infection with parasites and diseases were monitored between April and September 2014. The percentage of oilseed rape pollen was determined in pollen and honey samples. After oilseed rape flowering, the hives were transferred to an extensive isolated area for post-exposure monitoring. Total numbers of adult bees and brood cells showed seasonal fluctuations, and there were no significant differences between the sites. The honey, which was extracted at the end of the exposure phase, contained 62.0-83.5 % oilseed rape pollen. Varroa destructor infestation was low during most of the course of the study but increased at the end of the study due to flumethrin resistance in the mite populations. In summary, honey bee colonies foraging in clothianidin seed-treated oilseed rape did not show any detrimental symptoms as compared to colonies foraging in clothianidin-free oilseed rape. Development of colony strength, brood success as well as honey yield and pathogen infection were not significantly affected by clothianidin seed-treatment during this study.


Assuntos
Abelhas/fisiologia , Brassica napus/química , Monitoramento Ambiental , Guanidinas/toxicidade , Polinização/efeitos dos fármacos , Sementes/química , Tiazóis/toxicidade , Animais , Produtos Agrícolas , Alemanha , Insetos/fisiologia , Neonicotinoides , Sementes/toxicidade
7.
ChemSusChem ; 17(8): e202301154, 2024 Apr 22.
Artigo em Inglês | MEDLINE | ID: mdl-38179813

RESUMO

P2-type cobalt-free MnNi-based layered oxides are promising cathode materials for sodium-ion batteries (SIBs) due to their high reversible capacity and well chemical stability. However, the phase transformations during repeated (dis)charge steps lead to rapid capacity decay and deteriorated Na+ diffusion kinetics. Moreover, the electrode manufacturing based on polyvinylidene difluoride (PVDF) binder system has been reported with severely defluorination issue as well as the energy intensive and expensive process due to the use of toxic and volatile N-methyl-2-pyrrolidone (NMP) solvent. It calls for designing a sustainable, better performing, and cost-effective binder for positive electrode manufacturing. In this work, we investigated inorganic sodium metasilicate (SMS) as a viable binder in conjunction with P2-Na0.67Mn0.55Ni0.25Fe0.1Ti0.1O2 (NMNFT) cathode material for SIBs. The NMNFT-SMS electrode delivered a superior electrochemical performance compared to carboxy methylcellulose (CMC) and PVDF based electrodes with a reversible capacity of ~161 mAh/g and retaining ~83 % after 200 cycles. Lower cell impedance and faster Na+ diffusion was also observed in this binder system. Meanwhile, with the assistance of TEM technique, SMS is suggested to form a uniform and stable nanoscale layer over the cathode particle surface, protecting the particle from exfoliation/cracking due to electrolyte attack. It effectively maintained the electrode connectivity and suppressed early phase transitions during cycling as confirmed by operando XRD study. With these findings, SMS binder can be proposed as a powerful multifunctional binder to enable positive electrode manufacturing of SIBs and to overall reduce battery manufacturing costs.

8.
Clin Microbiol Infect ; 30(6): 816-821, 2024 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-38432432

RESUMO

OBJECTIVES: The diagnosis of invasive Candida infection remains challenging because of tests with slow turnaround times or mediocre performance. T2magnetic resonance imaging is a new diagnostic tool. We investigated the diagnostic accuracy of the T2Candida panel (T2) in comparison with blood culture (BC) and the SeptiFast (SF) for the detection of five different Candida species among high-risk intensive care unit patients with suspected candidemia. METHODS: We analysed blood samples collected from patients with suspected candidemia (177 samples from 138 patients) from August 2018 to April 2020. Blood samples were collected and analysed concurrently by BC, SF, and T2Candida. Subsequently, based on clinical and microbiological findings, patient samples were assigned to specific risk categories (proven, probable, and no candidemia). RESULTS: Twenty-two samples from 17 patients were classified as proven candidemia, and 15 samples from 14 patients were classified as probable candidemia. A sensitivity of 68.2% (95% CI, 45-86%) was observed for the BC and the SF, and a sensitivity of 63.6% (95% CI, 41-83%) was observed for the T2 when only cases with proven candidemia were evaluated. For proven and probable candidemia, the sensitivity was 40.5% (95% CI, 23-58%) for BC, 81.1% (95% CI, 65-92%) for SF, and 73.0% (95% CI, 56-86%) for T2. DISCUSSION: The diagnostic performance of SF and T2 was similar. For samples with proven/probable candidemia, SF and T2 had a higher sensitivity compared to BC. Used in conjunction with other diagnostic methods, T2 can replace the no longer available SF for the diagnosis of candidemia, enabling the timely initiation of targeted antifungal therapy.


Assuntos
Hemocultura , Candida , Candidemia , Sensibilidade e Especificidade , Humanos , Candidemia/diagnóstico , Candida/isolamento & purificação , Candida/classificação , Masculino , Feminino , Pessoa de Meia-Idade , Idoso , Hemocultura/métodos , Adulto , Idoso de 80 Anos ou mais , Unidades de Terapia Intensiva , Imageamento por Ressonância Magnética
9.
ACS Appl Mater Interfaces ; 16(20): 25953-25965, 2024 May 22.
Artigo em Inglês | MEDLINE | ID: mdl-38716923

RESUMO

Layered oxides constitute one of the most promising cathode materials classes for large-scale sodium-ion batteries because of their high specific capacity, scalable synthesis, and low cost. However, their practical use is limited by their low energy density, physicochemical instability, and poor cycling stability. Aiming to mitigate these shortcomings, in this work, we synthesized polycrystalline (PC) and single-crystal (SC) P2-type Na0.67-δMn0.67Ni0.33O2 (NMNO) cathode materials through a solid-state route and evaluated their physicochemical and electrochemical performance. The SC-NMNO cathode with a large mean primary particle size (D50) of 12.7 µm was found to exhibit high cycling stability leading to 47% higher capacity retention than PC-NMNO after 175 cycles at 1C rate in the potential window 4.2-1.5 V. This could be attributed to the effective mitigation of parasitic side reactions at the electrode-electrolyte interface and suppressed intergranular cracking induced by anisotropic volume changes. This is confirmed by the lower volume variation of SC-NMNO (ΔV ∼ 1.0%) compared to PC-NMNO (ΔV ∼ 1.4%) upon charging to 4.2 V. Additionally, the SC-NMNO cathode displayed slightly higher thermal stability compared to PC-NMNO. Both cathodes exhibited good chemical stability against air and water exposure, thus enabling material storage/handling in the ambient atmosphere as well as making them suitable for aqueous processing. In this regard, PC-NMNO was investigated with two low-cost aqueous binders, carboxymethyl cellulose, and sodium trimetaphosphate, which exhibited higher binding strength and displayed excellent electrochemical performance compared to PVDF, which could potentially lead to significant cost reduction in electrode manufacturing.

10.
J Bone Jt Infect ; 9(1): 87-97, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-38601005

RESUMO

Introduction: The BIOFIRE Joint Infection (JI) Panel is a diagnostic tool that uses multiplex-PCR testing to detect microorganisms in synovial fluid specimens from patients suspected of having septic arthritis (SA) on native joints or prosthetic joint infections (PJIs). Methods: A study was conducted across 34 clinical sites in 19 European and Middle Eastern countries from March 2021 to June 2022 to assess the effectiveness of the BIOFIRE JI Panel. Results: A total of 1527 samples were collected from patients suspected of SA or PJI, with an overall agreement of 88.4 % and 85 % respectively between the JI Panel and synovial fluid cultures (SFCs). The JI Panel detected more positive samples and microorganisms than SFC, with a notable difference on Staphylococcus aureus, Streptococcus species, Enterococcus faecalis, Kingella kingae, Neisseria gonorrhoeae, and anaerobic bacteria. The study found that the BIOFIRE JI Panel has a high utility in the real-world clinical setting for suspected SA and PJI, providing diagnostic results in approximately 1 h. The user experience was positive, implying a potential benefit of rapidity of results' turnover in optimising patient management strategies. Conclusion: The study suggests that the BIOFIRE JI Panel could potentially optimise patient management and antimicrobial therapy, thus highlighting its importance in the clinical setting.

11.
Proc Natl Acad Sci U S A ; 107(25): 11240-4, 2010 Jun 22.
Artigo em Inglês | MEDLINE | ID: mdl-20534519

RESUMO

Although texts and wall paintings suggest that bees were kept in the Ancient Near East for the production of precious wax and honey, archaeological evidence for beekeeping has never been found. The Biblical term "honey" commonly was interpreted as the sweet product of fruits, such as dates and figs. The recent discovery of unfired clay cylinders similar to traditional hives still used in the Near East at the site of Tel Re ov in the Jordan valley in northern Israel suggests that a large-scale apiary was located inside the town, dating to the 10th-early 9th centuries B.C.E. This paper reports the discovery of remains of honeybee workers, drones, pupae, and larvae inside these hives. The exceptional preservation of these remains provides unequivocal identification of the clay cylinders as the most ancient beehives yet found. Morphometric analyses indicate that these bees differ from the local subspecies Apis mellifera syriaca and from all subspecies other than A. m. anatoliaca, which presently resides in parts of Turkey. This finding suggests either that the Western honeybee subspecies distribution has undergone rapid change during the last 3,000 years or that the ancient inhabitants of Tel Re ov imported bees superior to the local bees in terms of their milder temper and improved honey yield.


Assuntos
Criação de Abelhas , Abelhas/fisiologia , Mel , Animais , Arqueologia , História Antiga , Humanos , Indústrias , Jordânia , Datação Radiométrica
12.
Sci Data ; 10(1): 43, 2023 01 19.
Artigo em Inglês | MEDLINE | ID: mdl-36658233

RESUMO

Electrolytes are considered crucial for the performance of batteries, and therefore indispensable for future energy storage research. This paper presents data that describes the effect of the electrolyte composition on the ionic conductivity. In particular, the data focuses on electrolytes composed of ethylene carbonate (EC), propylene carbonate (PC), ethyl methyl carbonate (EMC), and lithium hexafluorophosphate (LiPF6). The mass ratio of EC to PC was varied, while keeping the mass ratio of (EC + PC) and EMC at fixed values of 3:7 and 1:1. The conducting salt concentration was also varied during the study. Conductivity data was obtained from electrochemical impedance spectroscopy (EIS) measurements at various temperatures. Based on the thus obtained temperature series, the activation energy for ionic conduction was determined during the analysis. The data is presented here in a machine-readable format and includes a Python package for analyzing temperature series of electrolyte conductivity according to the Arrhenius equation and EIS data. The data may be useful e.g. for the training of machine learning models or for reference prior to experiments.

13.
Am J Infect Control ; 51(4): 406-412, 2023 04.
Artigo em Inglês | MEDLINE | ID: mdl-35870661

RESUMO

BACKGROUND: Hospital-acquired infections represent increasing problems in health-care facilities worldwide. Adequate infection control measures are key elements in preventing those infections. Expert societies have published recommendations that help to reduce Hospital-acquired infections. METHODS: In November 2019, a questionnaire-based point-prevalence survey, eliciting the adherence of 14 Tyrolean hospitals to the recommendations of the Centers of Disease Control and Prevention (CDC) was performed. Additionally, standard infection control measures performed by different medical (clinical and infection control specialists) disciplines as well as the performed infection control measures of nurses and physicians were compared. RESULTS: The survey revealed varying adherence to CDC-recommendations of different medical disciplines, with highest congruence by the infection control specialists and lower congruencies by all surveyed clinical disciplines. Concordance rate between nurses and physicians was high. DISCUSSION: Explanations for the varying congruencies of clinical disciplines on the one hand and the infection control specialists on the other hand may be versatile. Possible lacks of knowledge about the required hygiene measures should be taken into account. CONCLUSIONS: The present survey showed moderate adherence of Tyrolean hospitals to the recommendations provided by CDC, however with noticeable differences between different medical disciplines. Nurses and doctors in most cases reported identically.


Assuntos
Infecção Hospitalar , Médicos , Humanos , Áustria , Controle de Infecções , Hospitais , Infecção Hospitalar/prevenção & controle , Fidelidade a Diretrizes
14.
ACS Appl Mater Interfaces ; 15(32): 38391-38402, 2023 Aug 16.
Artigo em Inglês | MEDLINE | ID: mdl-37527285

RESUMO

The high ionic conductivity and good oxidation stability of halide-based solid electrolytes evoke strong interest in this class of materials. Nonetheless, the superior oxidative stability compared to sulfides comes at the expense of limited stability toward reduction and instability against metallic lithium anodes, which hinders their practical use. In this context, the gradual fluorination of Li2ZrCl6-xFx (0 ≤ x ≤ 1.2) is proposed to enhance the stability toward lithium-metal anodes. The mechanochemically synthesized fluorine-substituted compounds show the expected distorted local structure (M2-M3 site disorder) and significant change in the overall Li-ion migration barrier. Theoretical calculations reveal an approximate minimum energy path for Li2ZrCl6-xFx (x = 0 and 0.5) with an increase in the Li+ migration energy barrier for Li2ZrCl5.5F0.5 in comparison to Li2ZrCl6. However, it is found that the fluorine-substituted compound exhibits substantially lower polarization after 800 h of lithium stripping and plating owing to enhanced interfacial stability against the lithium metal, as revealed by density functional theory and ex situ X-ray photoelectron spectroscopy, thanks to the formation of a fluorine-rich passivating interphase.

15.
Trauma Case Rep ; 42: 100741, 2022 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-36465139

RESUMO

Traumatic or iatrogenic sciatic nerve injury, but not superior gluteal nerve injury, is a well described complication after acetabular fractures. Most often, sciatic nerve injuries occur in fractures involving the posterior column/wall with a hip dislocation and posterior fracture displacement resulting in narrowing of the greater sciatic foramen and injuring the sciatic nerve passing through. In this case report, a case of abductor mechanism deficiency with positive Trendelenburg's sign after an acetabular fracture of the posterior column with hip dislocation is presented. Postoperative clinical and MRI examination revealed a neurogenic atrophy of gluteus medius and minimus muscles suggesting a superior gluteal nerve injury due to initial subtotal incarceration of the greater sciatic foramen by a displaced posterior fracture fragment. An additional mild sciatic nerve injury resolved in the early postoperative course, while intensive physiotherapy improved the patient's complaints and muscular atrophy caused by the superior gluteal nerve injury within 12 months. This case report intends to raise awareness for rare neurological complications after acetabular fractures for their early detection.

16.
Insects ; 13(3)2022 Mar 15.
Artigo em Inglês | MEDLINE | ID: mdl-35323586

RESUMO

In Morocco, there are two well-recognised honey bee (Apis mellifera L.) subspecies: A. m. intermissa in the north and A. m. sahariensis in the south-east. The latter subspecies is found in the arid and semiarid climates of the Sahara Desert. In this study, we used honey bees from four areas of south-eastern Morocco which are, to some degree, isolated by arid zones. We analysed the shape and size of the forewings, using the method of geometric morphometrics. The bees from the four areas of south-eastern Morocco differed significantly in terms of wing shape. Moreover, bees from traditional hives were smaller than those from modern hives. The bees from south-eastern Morocco were clearly different from the reference samples obtained from the Morphometric Bee Data Bank in Oberursel, Germany, representing most of the global variation in honey bees. Surprisingly, the bees were also different from A. m. sahariensis, which should occur in the study area, according to earlier studies. This difference could have been caused by introgression with non-native subspecies imported by beekeepers. The distinct honey bees from south-eastern Morocco deserve to be protected. We provide a method for identifying them, which can help protect them.

17.
Naturwissenschaften ; 98(11): 967-75, 2011 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-21971844

RESUMO

The stridulation of the giant pill-millipede genus Sphaerotherium from South Africa, one of only three groups of millipedes that produce sounds, was studied. One hundred one stridulation series of a total of nine different species (Sphaerotherium dorsaloide, Sphaerotherium hanstroemi, Sphaerotherium mahaium, Sphaerotherium similare, Sphaerotherium punctulatum, Sphaerotherium convexitarsum, Sphaerotherium dorsale, Sphaerotherium rotundatum, and Sphaerotherium perbrincki) were analyzed. Stridulation sounds are produced only with a special field of ribs on the posterior surface of the posterior telopod, which is actively moved over a field of sclerotized nubs on the inner margin of the anal shield. The Sphaerotherium male usually stridulates only when in contact with a female to initiate mating. This seems to prevent the female from volvating into a ball or stimulate the female to uncoil when already rolled in. The sound analyzes revealed a broad frequency spectrum in all stridulation sounds produced, without obvious differences in frequency distribution among species. However, the temporal pattern of the stridulation varies greatly between species and seems to be species-specific, arguing for a species recognition function of the stridulation during courtship behavior. A single species (S. punctulatum) was found to stridulate during mating while three species also show postcopulatory stridulation. Apparently, pill-millipedes are not capable of acoustic perception, as no hearing organs are known, indicating that the communication is mainly based on perception of temporal vibration patterns, and not of the acoustic signal itself. The need to overcome the rolling-in reflex of the female is developed as a hypothesis why stridulation exists only in millipedes able to coil into a ball, and apparently evolved four times independently in the superorder Oniscomorpha.


Assuntos
Comunicação Animal , Artrópodes/anatomia & histologia , Artrópodes/fisiologia , Comportamento Sexual Animal/fisiologia , Acústica , Animais , Artrópodes/ultraestrutura , Tamanho Corporal/fisiologia , Feminino , Masculino , Microscopia Eletrônica de Varredura , Especificidade da Espécie
18.
Front Neurorobot ; 15: 647930, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-33935675

RESUMO

Shared autonomy aims at combining robotic and human control in the execution of remote, teleoperated tasks. This cooperative interaction cannot be brought about without the robot first recognizing the current human intention in a fast and reliable way so that a suitable assisting plan can be quickly instantiated and executed. Eye movements have long been known to be highly predictive of the cognitive agenda unfolding during manual tasks and constitute, hence, the earliest and most reliable behavioral cues for intention estimation. In this study, we present an experiment aimed at analyzing human behavior in simple teleoperated pick-and-place tasks in a simulated scenario and at devising a suitable model for early estimation of the current proximal intention. We show that scan paths are, as expected, heavily shaped by the current intention and that two types of Gaussian Hidden Markov Models, one more scene-specific and one more action-specific, achieve a very good prediction performance, while also generalizing to new users and spatial arrangements. We finally discuss how behavioral and model results suggest that eye movements reflect to some extent the invariance and generality of higher-level planning across object configurations, which can be leveraged by cooperative robotic systems.

19.
PLoS One ; 15(7): e0236252, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32726338

RESUMO

Despite the need to map research careers, the empirical evidence on career patterns of researchers is limited. We also do not know whether career patterns of researchers can be considered conventional in terms of steady progress or international mobility, nor do we know if career patterns differ between men and women in research as is commonly assumed. We use sequence analysis to identify career patterns of researchers across positions and institutions, based on full career histories of applicants to the European Research Council frontier research grant schemes. We distinguish five career patterns for early and established men and women researchers. With multinomial logit analyses, we estimate the relative likelihood of researchers with certain characteristics in each pattern. We find grantees among all patterns, and limited evidence of gender differences. Our findings on career patterns in research inform further studies and policy making on career development, research funding, and gender equality.


Assuntos
Pesquisa Biomédica/normas , Mobilidade Ocupacional , Pesquisadores/normas , Adulto , Europa (Continente) , Feminino , Organização do Financiamento , Humanos , Masculino , Pessoa de Meia-Idade , Pesquisadores/psicologia , Análise de Sequência , Inquéritos e Questionários , Universidades/normas
20.
Mitochondrial DNA B Resour ; 5(1): 875-876, 2020 Jan 27.
Artigo em Inglês | MEDLINE | ID: mdl-33366792

RESUMO

The mitochondrial genome of a worker Apis mellifera jemenitica was 16,623 bp. It consisted of 13 protein-coding genes, 22 transfer RNAs, two ribosomal RNAs and a control region. Phylogenetic analyses suggest a close relationship between A. m. jemenitica, A. m. lamarckii and A. m. syriaca.

SELEÇÃO DE REFERÊNCIAS
Detalhe da pesquisa