The biogeography of the Amazonian tree flora.

We describe the geographical variation in tree species composition across Amazonian forests and show how environmental conditions are associated with species turnover. Our analyses are based on 2023 forest inventory plots (1 ha) that provide abundance data for a total of 5188 tree species. Within-plot species composition reflected both local environmental conditions (especially soil nutrients and hydrology) and geographical regions.

Consistent patterns of common species across tropical tree communities.

Trees structure the Earth's most biodiverse ecosystem, tropical forests. The vast number of tree species presents a formidable challenge to understanding these forests, including their response to environmental change, as very little is known about most tropical tree species. A focus on the common species may circumvent this challenge.

Complex dynamics of induced vortex formation and thermal-fluid coupling in tri-hybrid nanofluid under localized magnetic field: a novel study.

Hybrid nanofluids offer higher stability, synergistic effects, and better heat transfer compared to simple nanofluids. Their higher thermal conductivity, lower viscosity, and interaction with magnetic fields make them ideal for various applications, including materials science, transportation, medical technology, energy, and fundamental physics. The governing partial differential equations are numerically solved by employing a finite volume approach, and the effects of various parameters on the nanofluid flow and thermal characteristics are systematically examined from the simulations based on a self-developed MATLAB code.

Mapping density, diversity and species-richness of the Amazon tree flora.

Using 2.046 botanically-inventoried tree plots across the largest tropical forest on Earth, we mapped tree species-diversity and tree species-richness at 0.1-degree resolution, and investigated drivers for diversity and richness.

More than 10,000 pre-Columbian earthworks are still hidden throughout Amazonia.

Indigenous societies are known to have occupied the Amazon basin for more than 12,000 years, but the scale of their influence on Amazonian forests remains uncertain. We report the discovery, using LIDAR (light detection and ranging) information from across the basin, of 24 previously undetected pre-Columbian earthworks beneath the forest canopy. Modeled distribution and abundance of large-scale archaeological sites across Amazonia suggest that between 10,272 and 23,648 sites remain to be discovered and that most will be found in the southwest.

Unraveling Amazon tree community assembly using Maximum Information Entropy: a quantitative analysis of tropical forest ecology.

In a time of rapid global change, the question of what determines patterns in species abundance distribution remains a priority for understanding the complex dynamics of ecosystems. The constrained maximization of information entropy provides a framework for the understanding of such complex systems dynamics by a quantitative analysis of important constraints via predictions using least biased probability distributions. We apply it to over two thousand hectares of Amazonian tree inventories across seven forest types and thirteen functional traits, representing major global axes of plant strategies.

Relationships between species richness and ecosystem services in Amazonian forests strongly influenced by biogeographical strata and forest types.

Despite increasing attention for relationships between species richness and ecosystem services, for tropical forests such relationships are still under discussion. Contradicting relationships have been reported concerning carbon stock, while little is known about relationships concerning timber stock and the abundance of non-timber forest product producing plant species (NTFP abundance). Using 151 1-ha plots, we related tree and arborescent palm species richness to carbon stock, timber stock and NTFP abundance across the Guiana Shield, and using 283 1-ha plots, to carbon stock across all of Amazonia.

Biased-corrected richness estimates for the Amazonian tree flora.

Amazonian forests are extraordinarily diverse, but the estimated species richness is very much debated. Here, we apply an ensemble of parametric estimators and a novel technique that includes conspecific spatial aggregation to an extended database of forest plots with up-to-date taxonomy. We show that the species abundance distribution of Amazonia is best approximated by a logseries with aggregated individuals, where aggregation increases with rarity.

Rarity of monodominance in hyperdiverse Amazonian forests.

Tropical forests are known for their high diversity. Yet, forest patches do occur in the tropics where a single tree species is dominant. Such "monodominant" forests are known from all of the main tropical regions.

Philadelphia Chromosome-Positive De Novo Acute Myeloid Leukemia Treated With Chemotherapy and Second-Generation Tyrosine Kinase Inhibitor.

Philadelphia chromosome-positive Acute Myeloid Leukemia (AML) is a de novo acute leukemia in which patients show no evidence of Chronic Myeloid Leukemia (CML) before or after their treatment. This kind of leukemia has an aggressive clinical course, with poor response to traditional chemotherapy or monotherapy with Tyrosine Kinase Inhibitors (TKI), and a high risk of early relapse after induction therapy. We report a rare case of de novo ALM with t(9;22).

Attacking the mosquito on multiple fronts: Insights from the Vector Control Optimization Model (VCOM) for malaria elimination.

Background: Despite great achievements by insecticide-treated nets (ITNs) and indoor residual spraying (IRS) in reducing malaria transmission, it is unlikely these tools will be sufficient to eliminate malaria transmission on their own in many settings today. Fortunately, field experiments indicate that there are many promising vector control interventions that can be used to complement ITNs and/or IRS by targeting a wide range of biological and environmental mosquito resources. The majority of these experiments were performed to test a single vector control intervention in isolation; however, there is growing evidence and consensus that effective vector control with the goal of malaria elimination will require a combination of interventions.

Persistent effects of pre-Columbian plant domestication on Amazonian forest composition.

The extent to which pre-Columbian societies altered Amazonian landscapes is hotly debated. We performed a basin-wide analysis of pre-Columbian impacts on Amazonian forests by overlaying known archaeological sites in Amazonia with the distributions and abundances of 85 woody species domesticated by pre-Columbian peoples. Domesticated species are five times more likely than nondomesticated species to be hyperdominant.

Estimating the global conservation status of more than 15,000 Amazonian tree species.

Estimates of extinction risk for Amazonian plant and animal species are rare and not often incorporated into land-use policy and conservation planning. We overlay spatial distribution models with historical and projected deforestation to show that at least 36% and up to 57% of all Amazonian tree species are likely to qualify as globally threatened under International Union for Conservation of Nature (IUCN) Red List criteria. If confirmed, these results would increase the number of threatened plant species on Earth by 22%.

The Role of Institutional Placement, Family Conflict, and Homosexuality in Homelessness Pathways Among Latino LGBT Youth in New York City.

Despite the overrepresentation of Lesbian, Gay, Bisexual, and Transgender (LGBT) youth among the homeless, the processes leading to their homelessness are understudied. This ethnographic study sought to elucidate the role of sexual orientation in the pathway to housing instability among young gay men. Fieldwork included 18 months of participant observations in public spaces and at a homeless LGBT youth organization in New York City, as well as formal semistructured interviews with 14 Latino young men and five staff.

Hyperdominance in the Amazonian tree flora.

The vast extent of the Amazon Basin has historically restricted the study of its tree communities to the local and regional scales. Here, we provide empirical data on the commonness, rarity, and richness of lowland tree species across the entire Amazon Basin and Guiana Shield (Amazonia), collected in 1170 tree plots in all major forest types. Extrapolations suggest that Amazonia harbors roughly 16,000 tree species, of which just 227 (1.

Changes in structure and composition of evergreen forests on an altitudinal gradient in the Venezuelan Guayana shield.

There have been several ecological studies in forests of the Guayana Shield, but so far none had examined the changes in structure and composition of evergreen forests with altitude. This study describes and analyzes the structure, species composition and soil characteristics of forest stands at different altitudinal zones in Southeastern Venezuelan Guayana, in order to explain the patterns and the main factors that determine the structure and composition of evergreen forests along the altitudinal gradient. Inventories of 3 948 big (>10cm DBH) and 1 328 small (5-10cm DBH) woody stems were carried out in eleven plots, ranging from 0.

Cephazolin-induced toxic epidermal necrolysis treated with intravenous immunoglobulin and N-acetylcysteine.

Toxic epidermal necrolysis is the most severe form of drug-induced skin reaction and includes denudation of >30% of total body surface area. The mechanism of disease is not completely understood, but immunologic mechanisms, cytotoxic reactions, and delayed hypersensitivity seem to be involved. We report a case of cephazolin-induced toxic epidermal necrolysis treated with intravenous immunoglobulin and N-acetylcysteine with excellent response.

Continental-scale patterns of canopy tree composition and function across Amazonia.

The world's greatest terrestrial stores of biodiversity and carbon are found in the forests of northern South America, where large-scale biogeographic patterns and processes have recently begun to be described. Seven of the nine countries with territory in the Amazon basin and the Guiana shield have carried out large-scale forest inventories, but such massive data sets have been little exploited by tropical plant ecologists. Although forest inventories often lack the species-level identifications favoured by tropical plant ecologists, their consistency of measurement and vast spatial coverage make them ideally suited for numerical analyses at large scales, and a valuable resource to describe the still poorly understood spatial variation of biomass, diversity, community composition and forest functioning across the South American tropics.

Successfully establishing laparoscopic surgery programs in developing countries. Clinical results and lessons learned.

Background: Laparoscopic surgery has not been widely established in developing countries due to the lack of access to training and lack of money. We describe our experience using on-site training programs to efficiently teach and propagate laparoscopic surgery in Leon, Nicaragua; La Paz, Bolivia; and Santa Cruz, Bolivia.

Methods: A group of well-trained and motivated local surgeons was identified in each country as the initial target for teaching.

Operative enteroscopy. A useful tool in the evaluation and intervention of bilioenteric anastomoses.

Roux-en-Y hepaticojejunostomy is the procedure of choice in the management of patients with major bile duct injuries. In instances of anastomotic stricture, this anastomosis is inaccessible to conventional endoscopy. A technique is described for assessment and intervention of bilioenteric anastomoses that escape the reach of conventional endoscopy.

Sigmoid volvulus in the high altitude of the Andes. Review of 230 cases.

Sigmoid volvulus (SV) is uncommon in the United States. Little has been published in the English literature about the high incidence of SV among rural areas of the Bolivian and Peruvian Andes at 13,000 feet above sea level. A review of 230 cases of SV in a Bolivian hospital is presented.

Heparin effect on plasma fibrinogen in the thrombophilic syndrome.

The effects of heparin were studied in a group of 42 patients with preinfarction angina (PA) and acute myocardial infarction (AMI) whose plasma fibrinogen was increased. Plasma fibrinogen was measured by the turbidimetric method in timol turbidimetric units. Statistically significant results proved that heparin reduces the plasma fibrinogen progressively over a treatment period of 6 weeks.