Shaping the laser control landscape of a hydrogen transfer reaction by vibrational strong coupling. A direct optimal control approach.

Controlling molecular reactivity by shaped laser pulses is a long-standing goal in chemistry. Here, we suggest a direct optimal control approach that combines external pulse optimization with other control parameters arising in the upcoming field of vibro-polaritonic chemistry for enhanced controllability. The direct optimal control approach is characterized by a simultaneous simulation and optimization paradigm, meaning that the equations of motion are discretized and converted into a set of holonomic constraints for a nonlinear optimization problem given by the control functional. Compared with indirect optimal control, this procedure offers great flexibility, such as final time or Hamiltonian parameter optimization. A simultaneous direct optimal control theory will be applied to a model system describing H-atom transfer in a lossy Fabry-Pérot cavity under vibrational strong coupling conditions. Specifically, optimization of the cavity coupling strength and, thus, of the control landscape will be demonstrated.

Storylines for unprecedented heatwaves based on ensemble boosting.

Recent temperature extremes have shattered previously observed records, reaching intensities that were inconceivable before the events. Could the possibility of an event with such unprecedented intensity as the 2021 Pacific Northwest heatwave have been foreseen, based on climate model information available before the event? Could the scientific community have quantified its potential intensity based on the current generation of climate models? Here, we demonstrate how an ensemble boosting approach can be used to generate physically plausible storylines of a heatwave hotter than observed in the Pacific Northwest. We also show that heatwaves of much greater intensities than ever observed are possible in other locations like the Greater Chicago and Paris regions. In order to establish confidence in storylines of 'black swan'-type events, different lines of evidence need to be combined along with process understanding to make this information robust and actionable for stakeholders.

[The clinical importance of the critical view of safety in laparoscopic cholecystectomy]. / Die klinische Bedeutung des "critical view of safety" in der laparoskopischen Gallenblasenchirurgie.

BACKGROUND: Injury of the bile duct during cholecystectomy (CHE) is a severe complication. The critical view of safety (CVS) can help to reduce the frequency of this complication during laparoscopic CHE. So far, no scoring of CVS images with a grading system is available. METHOD: The CVS images of 534 patients with laparoscopic CHE could be structurally analyzed and assessed with marks from 1 (very good) to 5 (insufficient). The CVS mark was correlated with the perioperative course. Additionally, the perioperative course of patients after laparoscopic CHE with and without a CVS image was investigated. RESULTS: In 534 patients 1 or more CVS images could be analyzed. The average CVS mark was 1.9, whereby 280 patients (52.4%) had a 1, 126 patients (23.6%) a 2, 114 (21.3%) a 3 and 14 patients (2.6%) a 4 or 5. Younger patients with elective laparoscopic CHE had CVS images significantly more frequently (p ≤ 0.04). The statistical examination with Pearson's χ2-test and the F­test (ANOVA) showed a significant correlation between improving CVS marks and reduction of surgery time (p < 0.01) and the hospitalization time (p < 0.01). For senior physicians the quota of CVS images ranged from 71% to 92% and the average marks from 1.5 to 2.2. The marks for the CVS images were significantly better for female than male patients (1.8 vs. 2.1, p < 0.01). DISCUSSION: There was a relatively broad distribution of marks for CVS images. Injuries of the bile duct can be avoided with a high degree of certainty with marks 1­2 for the CVS image. The CVS is not always adequately visualized in laparoscopic CHE.

Occupation as means and ends in paediatric occupational therapy - A systematic review.

BACKGROUND: There is a lack of evidence-based knowledge in paediatric occupational therapy about the effectiveness of interventions using daily activities as a treatment modality in improving children's participation. OBJECTIVE: This study aimed to evaluate the effectiveness of occupation-based and occupation-focused interventions in improving participation in everyday occupations for young children with a disability. MATERIAL AND METHODS: A systematic review based on Joanna Briggs Institute methodology and critical appraisal tools was conducted. Six databases were searched for quantitative intervention studies aimed at improving participation in everyday occupations of young children with a disability through the use of everyday occupation. RESULTS: The search yielded 3732 records, of which 13 studies met inclusion criteria. Ten studies met methodological quality criteria and were included in the synthesis, five randomised controlled trials and five quasi-experimental studies, involving a total of 424 children with a mean age of 6.5 years. The studies were classified into cognitive (n = 5), context-focussed (n = 2) and playgroup interventions (n = 3). Study quality ranged from low to moderate, only one study was rated high quality. CONCLUSIONS AND SIGNIFICANCE: Occupation-based and occupation-focused interventions may have a positive effect on participation in everyday occupations for young children with a disability, but study design, risk of bias and insufficient reporting limit confidence in the body of evidence.

[The COVID-19 pandemic had significant impact on duration of surgery and hospitalization time for patients after cholecystectomy]. / Die Auswirkungen der COVID-19 Pandemie führten zu signifikanten Veränderungen der Operations- und Liegezeiten bei Patienten nach Cholezystektomie.

BACKGROUND: The COVID-19 pandemic made substantial changes in medical care necessary. The aims of this study were to find out what influence the pandemic had on the perioperative course in patients with cholecystectomy (CHE) and to highlight possible residual consequences. METHOD: From 1 July 2018 to 31 December 2021 a total of 735 patients with CHE were analyzed. Up to 21 March 2020 patients were assigned to the regular patient group (Reg, n = 430), patients after this date (first lockdown 22 March 2020) to the Cov19 patient group (Cov19, n = 305) and the 2 groups were compared. RESULTS: The average age of all patients was 59 years and 63% were women. The average length of hospitalization (KrVD, time period between surgery and discharge) was 4.4 days. The patient groups Reg and Cov19 did not differ with respect to age, gender or KrVD. The total number of CHEs carried out was reduced by 21.4% in the Cov19 group. This affected elective and emergency CHE to the same extent. The length of surgery significantly increased in the Cov19 group from 64 min (SD 34 min) to 71 min (SD 38 min). The number of short and long hospital stays (KrVD 2 or >4 days) significantly increased in the Cov19 group from 4 % to 20 % (short stay, p < 0.01) and from 23 % to 27 % (long stay, p < 0.01). This was particularly observed for patients >70 years old with an increase in long stays from 43 % to 56 % in the Cov19 group. CONCLUSION: The COVID-19 pandemic led to a clear reduction in CHE both for elective and emergency interventions. Furthermore, a significant lengthening of the surgery and hospitalization times could be observed for older patients. The residual consequences of the pandemic could be shortened hospitalization times after uncomplicated CHE and more interventional treatment procedures in complex cases.

Woody species distribution across a savanna-dry forest soil gradient in the Brazilian Cerrado / Distribuição de espécies arbóreas em gradiente de solo savana-floresta seca no Cerrado brasileiro

Abstract Although richness and distribution of woody species in the Cerrado physiognomies have been extensively studied, the shifts of woody species from savanna physiognomies to dry forests have not yet been addressed. Here, we investigate the effect of soil physical-chemical traits on the woody species turnover between adjacent cerrado stricto sensu and dry forest physiognomies. Woody species were surveyed, and soil and topographic variables measured, in 30 10×40 m plots systematically distributed, with 15 plots in each physiognomy. We found a spatially structured distribution of woody species, and differences of soil traits between cerrado stricto sensu and dry forest areas, mainly related to the aluminum saturation, base saturation, and available phosphorus. Aluminum saturation increased toward the savanna area, while base saturation increased toward the dry forest. Most woody species predominated in one physiognomy, such as Callisthene major in the cerrado stricto sensu and Anadenanthera colubrina in the dry forest. Only 20% of the species were widely distributed across both physiognomies or, not often, restricted to the intermediary values of the soil gradient. General results indicate that contrasting soil traits between cerrado stricto sensu and dry forest produce a strongly spatially organized and sharp transition in terms of species distribution between these physiognomies.

Resumo Embora a distribuição e a riqueza em espécies arbóreas nas fitofisionomias do Cerrado venham sendo bastante estudadas, a transição entre savanas e florestas deciduais ainda não foi abordada. Investigamos o efeito de características físico-químicas do solo sobre a distribuição de espécies arbóreas em região de contato entre cerrado sentido restrito e floresta estacional decidual (FED). As espécies arbóreas foram amostradas sistematicamente, e variáveis de topografia e características do solo foram medidas em 30 parcelas de 10×40 m, sendo 15 parcelas em cada fisionomia. A distribuição das espécies arbóreas foi espacialmente estruturada, e as características do solo diferiram entre as áreas de cerrado sentido restrito e FED, principalmente relacionadas à saturação de alumínio, saturação de bases e teores de fósforo. A saturação de alumínio aumentou em direção ao cerrado sentido restrito, enquanto a saturação de bases aumentou em direção à FED. A maioria das espécies arbóreas predominou em uma das fisionomias, como Callisthene major em cerrado sentido restrito e Anadenanthera colubrina em FED. Apenas 20% das espécies foram amplamente distribuídas em ambas as fisionomias ou, em poucos casos, restritas aos valores intermediários do gradiente de solo. Os resultados indicam um forte contraste de características do solo entre o cerrado sentido restrito e a FED, assim como uma transição acentuada e espacialmente organizada quanto à distribuição de espécies arbóreas.

Woody species distribution across a savanna-dry forest soil gradient in the Brazilian Cerrado / Distribuição de espécies arbóreas em gradiente de solo savana-floresta seca no Cerrado brasileiro

Although richness and distribution of woody species in the Cerrado physiognomies have been extensively studied, the shifts of woody species from savanna physiognomies to dry forests have not yet been addressed. Here, we investigate the effect of soil physical-chemical traits on the woody species turnover between adjacent cerrado stricto sensu and dry forest physiognomies. Woody species were surveyed, and soil and topographic variables measured, in 30 10×40 m plots systematically distributed, with 15 plots in each physiognomy. We found a spatially structured distribution of woody species, and differences of soil traits between cerrado stricto sensu and dry forest areas, mainly related to the aluminum saturation, base saturation, and available phosphorus. Aluminum saturation increased toward the savanna area, while base saturation increased toward the dry forest. Most woody species predominated in one physiognomy, such as Callisthene major in the cerrado stricto sensu and Anadenanthera colubrina in the dry forest. Only 20% of the species were widely distributed across both physiognomies or, not often, restricted to the intermediary values of the soil gradient. General results indicate that contrasting soil traits between cerrado stricto sensu and dry forest produce a strongly spatially organized and sharp transition in terms of species distribution between these physiognomies.

Embora a distribuição e a riqueza em espécies arbóreas nas fitofisionomias do Cerrado venham sendo bastante estudadas, a transição entre savanas e florestas deciduais ainda não foi abordada. Investigamos o efeito de características físico-químicas do solo sobre a distribuição de espécies arbóreas em região de contato entre cerrado sentido restrito e floresta estacional decidual (FED). As espécies arbóreas foram amostradas sistematicamente, e variáveis de topografia e características do solo foram medidas em 30 parcelas de 10×40 m, sendo 15 parcelas em cada fisionomia. A distribuição das espécies arbóreas foi espacialmente estruturada, e as características do solo diferiram entre as áreas de cerrado sentido restrito e FED, principalmente relacionadas à saturação de alumínio, saturação de bases e teores de fósforo. A saturação de alumínio aumentou em direção ao cerrado sentido restrito, enquanto a saturação de bases aumentou em direção à FED. A maioria das espécies arbóreas predominou em uma das fisionomias, como Callisthene major em cerrado sentido restrito e Anadenanthera colubrina em FED. Apenas 20% das espécies foram amplamente distribuídas em ambas as fisionomias ou, em poucos casos, restritas aos valores intermediários do gradiente de solo. Os resultados indicam um forte contraste de características do solo entre o cerrado sentido restrito e a FED, assim como uma transição acentuada e espacialmente organizada quanto à distribuição de espécies arbóreas.

Woody species distribution across a savanna-dry forest soil gradient in the Brazilian Cerrado

Abstract Although richness and distribution of woody species in the Cerrado physiognomies have been extensively studied, the shifts of woody species from savanna physiognomies to dry forests have not yet been addressed. Here, we investigate the effect of soil physical-chemical traits on the woody species turnover between adjacent cerrado stricto sensu and dry forest physiognomies. Woody species were surveyed, and soil and topographic variables measured, in 30 10×40 m plots systematically distributed, with 15 plots in each physiognomy. We found a spatially structured distribution of woody species, and differences of soil traits between cerrado stricto sensu and dry forest areas, mainly related to the aluminum saturation, base saturation, and available phosphorus. Aluminum saturation increased toward the savanna area, while base saturation increased toward the dry forest. Most woody species predominated in one physiognomy, such as Callisthene major in the cerrado stricto sensu and Anadenanthera colubrina in the dry forest. Only 20% of the species were widely distributed across both physiognomies or, not often, restricted to the intermediary values of the soil gradient. General results indicate that contrasting soil traits between cerrado stricto sensu and dry forest produce a strongly spatially organized and sharp transition in terms of species distribution between these physiognomies.

Resumo Embora a distribuição e a riqueza em espécies arbóreas nas fitofisionomias do Cerrado venham sendo bastante estudadas, a transição entre savanas e florestas deciduais ainda não foi abordada. Investigamos o efeito de características físico-químicas do solo sobre a distribuição de espécies arbóreas em região de contato entre cerrado sentido restrito e floresta estacional decidual (FED). As espécies arbóreas foram amostradas sistematicamente, e variáveis de topografia e características do solo foram medidas em 30 parcelas de 10×40 m, sendo 15 parcelas em cada fisionomia. A distribuição das espécies arbóreas foi espacialmente estruturada, e as características do solo diferiram entre as áreas de cerrado sentido restrito e FED, principalmente relacionadas à saturação de alumínio, saturação de bases e teores de fósforo. A saturação de alumínio aumentou em direção ao cerrado sentido restrito, enquanto a saturação de bases aumentou em direção à FED. A maioria das espécies arbóreas predominou em uma das fisionomias, como Callisthene major em cerrado sentido restrito e Anadenanthera colubrina em FED. Apenas 20% das espécies foram amplamente distribuídas em ambas as fisionomias ou, em poucos casos, restritas aos valores intermediários do gradiente de solo. Os resultados indicam um forte contraste de características do solo entre o cerrado sentido restrito e a FED, assim como uma transição acentuada e espacialmente organizada quanto à distribuição de espécies arbóreas.

Gargle pool PCR testing in a hospital during medium and high SARS-CoV-2 incidence.

BACKGROUND: Hospitals need to be protected from SARS-CoV-2 infections to protect vulnerable patients. Thus, a safe, efficient, and cost-effective SARS-CoV-2 testing system for hospitals, in addition to standard hygiene measures and vaccination of staff, is necessary. Here we report on the feasibility and performance of a pool real-time reverse-transcriptase polymerase-chain-reaction (rRT-PCR) test system at, medium and high incidence. METHODS: We implemented a testing concept based on gargling at home and pooling of samples in the hospital before PCR testing in the laboratory. We used two PCR systems (point of care and standard 96-well plate system) to adapt to challenges in the hospital setting and respond to a rising incidence in the Omicron wave. FINDINGS: During our 10-week study period, we performed 697 pool PCRs (8793 tests in total) and identified 65 asymptomatic staff members by pool PCR and 94 symptomatic staff members by positive individual PCR. Virus loads in those detected by pool testing were significantly lower (P<0.001). The test system remained workable even during the peak of the Omicron wave and no outbreaks occurred in any specific area of the hospital during the study period. Unvaccinated individuals were over-represented in the positively tested (37% vs 22% positive tests, P=0.04). The test procedure was well accepted by a majority of the hospital staff (84%). CONCLUSION: Repeated gargle pool rRT-PCR testing can be implemented quickly in hospitals and is an effective, easily adaptable and well-accepted test system for hospitals, even during phases with very high infection rates.

A pilot trial of quetiapine, lithium, or placebo added to divalproex sodium for hypomanic or manic episodes in ambulatory adults with bipolar I disorder.

BACKGROUND: Many patients with bipolar I disorder do not respond to monotherapy treatment with mood-stabilizing medications, and combination regimens are commonly used in both inpatient and outpatient settings for the acute and maintenance treatment of bipolar disorder. We studied whether combination therapy is more effective than monotherapy for the acute treatment of subjects with bipolar I disorder currently experiencing manic symptoms. The primary hypothesis was that combination treatments would be associated with greater reductions in symptoms of mania and hypomania than monotherapy alone. The secondary hypothesis was that combination therapies would be associated with lower depression levels than monotherapy alone. Last, a post-hoc exploratory aim was used to examine whether the effect of side effect severity on risk-of-dropout would be greater in combination therapies than in monotherapy alone. RESULTS: In this 12-week, double-blind, placebo-controlled ambulatory pilot trial, participants (n = 75) with bipolar I disorder were randomly assigned to: (1) monotherapy divalproex plus placebo (DVP + PBO), (2) combination therapy of divalproex plus blinded lithium (DVP + Li) or (3) divalproex plus blinded quetiapine (DVP + QTP). Combination therapies (vs. monotherapy) were not associated with improved symptoms of mania, hypomania or depression. The effect of side effect severity on study retention did not differ between combination therapies and monotherapy. However, the risk-of-dropout was significantly greater in the DVP + Li arm versus the DVP + PBO arm. CONCLUSIONS: No longitudinal differences in mania, hypomania or depression were found between combination therapies and monotherapy. The effect of side effect severity on study retention did not differ between groups. Due to the small sample size and differential rates of attrition between treatment arms, results of this pilot trial must be interpreted with caution. Trial registration ClinicalTrials.gov identifier: NCT00183443.

The Mars Environmental Dynamics Analyzer, MEDA. A Suite of Environmental Sensors for the Mars 2020 Mission.

NASA's Mars 2020 (M2020) rover mission includes a suite of sensors to monitor current environmental conditions near the surface of Mars and to constrain bulk aerosol properties from changes in atmospheric radiation at the surface. The Mars Environmental Dynamics Analyzer (MEDA) consists of a set of meteorological sensors including wind sensor, a barometer, a relative humidity sensor, a set of 5 thermocouples to measure atmospheric temperature at ∼1.5 m and ∼0.5 m above the surface, a set of thermopiles to characterize the thermal IR brightness temperatures of the surface and the lower atmosphere. MEDA adds a radiation and dust sensor to monitor the optical atmospheric properties that can be used to infer bulk aerosol physical properties such as particle size distribution, non-sphericity, and concentration. The MEDA package and its scientific purpose are described in this document as well as how it responded to the calibration tests and how it helps prepare for the human exploration of Mars. A comparison is also presented to previous environmental monitoring payloads landed on Mars on the Viking, Pathfinder, Phoenix, MSL, and InSight spacecraft.

Postpartum atypical hemolytic uremic syndrome: Evaluating thrombotic microangiopathy in the pregnant woman.

Acute kidney injury in women during pregnancy and the puerperium is often ascribed to hypertensive complications of pregnancy, especially pre-eclampsia. However, rarer causes, including atypical hemolytic uremic syndrome (aHUS) can be triggered by pregnancy. We present a case of a woman with post-partum acute kidney injury due to aHUS, which was successfully treated with the C5a inhibitor eculizumab. We also present a summary of the evaluation and management of thrombotic microangiopathy in pregnancy.

Woody species distribution across a savanna-dry forest soil gradient in the Brazilian Cerrado.

Although richness and distribution of woody species in the Cerrado physiognomies have been extensively studied, the shifts of woody species from savanna physiognomies to dry forests have not yet been addressed. Here, we investigate the effect of soil physical-chemical traits on the woody species turnover between adjacent cerrado stricto sensu and dry forest physiognomies. Woody species were surveyed, and soil and topographic variables measured, in 30 10×40 m plots systematically distributed, with 15 plots in each physiognomy. We found a spatially structured distribution of woody species, and differences of soil traits between cerrado stricto sensu and dry forest areas, mainly related to the aluminum saturation, base saturation, and available phosphorus. Aluminum saturation increased toward the savanna area, while base saturation increased toward the dry forest. Most woody species predominated in one physiognomy, such as Callisthene major in the cerrado stricto sensu and Anadenanthera colubrina in the dry forest. Only 20% of the species were widely distributed across both physiognomies or, not often, restricted to the intermediary values of the soil gradient. General results indicate that contrasting soil traits between cerrado stricto sensu and dry forest produce a strongly spatially organized and sharp transition in terms of species distribution between these physiognomies.

Gongylolepis martiana, an Asteraceae pollinated by bats in the Amazon.

Most Asteraceae species are pollinated by insects, mainly bees and butterflies, although pollination by birds has been documented and pollination by bats has been suggested for some species. Here, we investigated the pollination of Gongylolepis martiana, a species supposedly pollinated by bats. We assessed floral traits and visitors in a population of G. martiana in the Brazilian Amazon, measuring pollen removal from anthers and deposition on stigmas by diurnal and nocturnal visitors. Florets opened at dusk and lasted for 4 days, with the male phase starting on the first night and the female phase on the third night. Accumulated nectar per capitulum was 69.6 µl per night and sugar concentration was 15%. Nectar-feeding bats and hummingbirds contacted the sexual parts, but pollen removal and deposition were greater throughout the night than during the day, when Meliponini bees considerably reduced pollen availability. Other nocturnal visitors of G. martiana were rare, including nocturnal bees and moths that foraged for pollen and nectar, respectively. Our results support that nectarivorous bats are the main pollinators of G. martiana, confirming Vogel's hypothesis of bat pollination in Asteraceae, particularly in the genus Gongylolepis. Since anthesis and each sexual floral phase started in the evening, nectarivorous bats and diurnal bees caused additive priority effects, preventing hummingbirds from being efficient pollinators. The high density of flowering individuals of G. martiana in patches from white-sand forests likely increases bat attraction, while the small amount of nectar per plant favours cross-pollination.

Wildfire Smoke Is Associated With an Increased Risk of Cardiorespiratory Emergency Department Visits in Alaska.

Alaskan wildfires have major ecological, social, and economic consequences, but associated health impacts remain unexplored. We estimated cardiorespiratory morbidity associated with wildfire smoke (WFS) fine particulate matter with a diameter less than 2.5 µm (PM2.5) in three major population centers (Anchorage, Fairbanks, and the Matanuska-Susitna Valley) during the 2015-2019 wildfire seasons. To estimate WFS PM2.5, we utilized data from ground-based monitors and satellite-based smoke plume estimates. We implemented time-stratified case-crossover analyses with single and distributed lag models to estimate the effect of WFS PM2.5 on cardiorespiratory emergency department (ED) visits. On the day of exposure to WFS PM2.5, there was an increased odds of asthma-related ED visits among 15-65 year olds (OR = 1.12, 95% CI = 1.08, 1.16), people >65 years (OR = 1.15, 95% CI = 1.01, 1.31), among Alaska Native people (OR = 1.16, 95% CI = 1.09, 1.23), and in Anchorage (OR = 1.10, 95% CI = 1.05, 1.15) and Fairbanks (OR = 1.12, 95% CI = 1.07, 1.17). There was an increased risk of heart failure related ED visits for Alaska Native people (Lag Day 5 OR = 1.13, 95% CI = 1.02, 1.25). We found evidence that rural populations may delay seeking care. As the frequency and magnitude of Alaskan wildfires continue to increase due to climate change, understanding the health impacts will be imperative. A nuanced understanding of the effects of WFS on specific demographic and geographic groups facilitates data-driven public health interventions and fire management protocols that address these adverse health effects.

Mites (Mesostigmata: Melicharidae) associated with hummingbirds (Aves: Trochilidae) in Brazil

Mites of the family Melicharidae comprise 13 genera and 220 species often associated with edaphic environments and found in association with insects, birds and mammals. Two genera, Proctolaelaps and Tropicoseius, have been recorded in Brazil in association with birds and bromeliads. In this study, we add new locality and host-association records for Proctolaelaps superagui and Tropicoseius braziliensis in the country.

Frequency of extreme precipitation increases extensively with event rareness under global warming.

The intensity of the heaviest extreme precipitation events is known to increase with global warming. How often such events occur in a warmer world is however less well established, and the combined effect of changes in frequency and intensity on the total amount of rain falling as extreme precipitation is much less explored, in spite of potentially large societal impacts. Here, we employ observations and climate model simulations to document strong increases in the frequencies of extreme precipitation events occurring on decadal timescales. Based on observations we find that the total precipitation from these intense events almost doubles per degree of warming, mainly due to changes in frequency, while the intensity changes are relatively weak, in accordance to previous studies. This shift towards stronger total precipitation from extreme events is seen in observations and climate models, and increases with the strength - and hence the rareness - of the event. Based on these results, we project that if historical trends continue, the most intense precipitation events observed today are likely to almost double in occurrence for each degree of further global warming. Changes to extreme precipitation of this magnitude are dramatically stronger than the more widely communicated changes to global mean precipitation.

Xiphidiocercariae from naturally infected Lymnaea columella (Mollusca, Gastropoda) in urban area: morphology and ultrastructure of the larvae and histological changes in the mollusc host / Xifidiocercárias obtidas em Lymnaea columella (Mollusca, Gastropoda) naturalmente infectadas em área urbana: morfologia e ultraestrutura da larva e alterações histológicas do molusco hospedeiro

Abstract Urban agriculture is very common in the cities, as Rio de Janeiro and adjacencies, being important as economic activity. However, this practice can create appropriate conditions for establishment and maintenance of life cycle of many parasites. Lymneid snails can act as intermediate hosts of many trematodes species, including those that infect humans and wild and domestic. In the present study, the snail Lymnaea columella was collected from an urban watercress plantations and the morphology of cercariae released by them was analyzed by light and scanning electron microscopy. The specimens were identified as xiphidiocercariae, belonging to the Cercariae Ornatae group, of the order Plagiorchiiformes. Histological examination of the digestive gland of the infected snails revealed the presence of developing sporocysts, with hemocitary infiltration and metaplasia in the epithelial tissue.

Resumo Agricultura urbana é muito comum nas cidades, como Rio de Janeiro e adjacências, sendo uma importante atividade econômica de subsistência. No entanto, esta prática pode criar condições adequadas para o estabelecimento e manutenção do ciclo de vida de muitos parasitos. Os moluscos limneídeos podem atuar como hospedeiros intermédios de muitas espécies de trematódeos, incluindo aqueles que infectam humanos e animais selvagens e domésticos. No presente estudo, o molusco Lymnaea columella foi coletado de plantações urbanas de agrião e a morfologia das cercárias liberadas por eles foi analisada por microscopia eletrônica de varredura leve e de varredura. As larvas foram identificadas como xifidiocercárias, pertencentes ao grupo das Cercariae Ornatae, Ordem Plagiorchiiformes. Análises histológicas da glândula digestiva dos moluscos infectados evidenciaram esporocistos, com formação de granuloma e metaplasia do tecido epitelial.

A quantum-mechanical tier model for phonon-driven vibrational relaxation dynamics of adsorbates at surfaces.

We present a quantum-mechanical tier model for vibrational relaxation of low-lying excited states of an adsorbate vibrational mode (system), coupled to surface phonons (bath), at zero temperature. The tier model, widely used in studies of intramolecular vibrational energy redistribution in polyatomics, is adapted here to adsorbate-surface systems with the help of an embedded cluster approach, using orthogonal coordinates for the system and bath modes, and a phononic expansion of their interaction. The key idea of the model is to organize the system-bath zeroth-order vibrational space into a hierarchical structure of vibrational tiers and keep therein only vibrational states that are sequentially generated from the system-bath initial vibrational state. Each tier is generated from the previous one by means of a successor operator, derived from the system-bath interaction Hamiltonian. This sequential procedure leads to a drastic reduction of the dimension of the system-bath vibrational space. We notably show that for harmonic vibrational motion of the system and linear system-bath couplings in the system coordinate, the dimension of the tier-model vibrational basis scales as ∼Nl×υ. Here, N is the number of bath modes, l is the highest-order of the phononic expansion, and υ is the size of the system vibrational basis. This polynomial scaling is computationally far superior to the exponential scaling of the original zeroth-order vibrational basis, ∼MN, with M being the number of basis functions per bath mode. In addition, since each tier is coupled only to its adjacent neighbors, the matrix representation of the system-bath Hamiltonian in this new vibrational basis has a symmetric block-tridiagonal form, with each block being very sparse. This favors the combination of the tier-model with iterative Krylov techniques, such as the Lanczos algorithm, to solve the time-dependent Schrödinger equation for the full Hamiltonian. To illustrate the method, we study vibrational relaxation of a D-Si bending mode, coupled via two- and (mainly) one-phonon interactions to a fully D-covered Si(100)-(2 × 1) surface, using a recent first-principles system-bath Hamiltonian. The results of the tier model are compared with those obtained by the Lindblad formalism of the reduced density matrix. We find that the tier model provides much more information and insight into mechanisms of vibration-phonon couplings at surfaces, and gives more reliable estimates of the adsorbate vibrational lifetimes. Moreover, the tier model might also serve as a benchmark for other approximate quantum-dynamics methods, such as multiconfiguration wavefunction approaches.

Nectar traits differ between pollination syndromes in Balsaminaceae.

BACKGROUND AND AIMS: The attractiveness of nectar rewards depends both on the quantity of nectar produced and on its chemical composition. It is known that nectar quantity and chemical composition can differ in plant species depending on the main pollinator associated with the species. The main aims of this study were to test formally whether nectar traits are adapted to pollination syndromes in the speciose Balsaminaceae and, if so, whether a combination of nectar traits mirrors pollination syndromes. METHODS: Comparative methods based on Ornstein-Uhlenbeck models were used to test whether nectar volume, nectar sucrose proportion, sugar and amino acid concentration and amino acid composition had evolved as a function of pollination syndromes in 57 species of Balsaminaceae. Cluster analysis and ordination were performed to derive clusters of species resembling each other in nectar composition. KEY RESULTS: Evolutionary models for nectar volume and nectar sucrose proportion performed best when including information on pollination syndrome, while including such information improve model fit neither for sugar and amino acid concentration nor for amino acid composition. A significant relationship emerged between pollination syndrome and the combined nectar traits. CONCLUSIONS: Our results show that nectar volume and nectar sucrose proportion evolve rapidly towards optimal values associated with different pollination syndromes. The detection of a signal indicating that nectar traits in combination are to a certain extent able to predict pollination syndromes in Balsaminaceae suggests that a holistic approach including the whole set of nectar traits helps us to better understand evolution of nectar composition in response to pollinators.