308 results match your criteria: "University of Puerto Rico-Rio Piedras[Affiliation]"

The evolution of mimicry in similarly defended prey is well described by the Müllerian mimicry theory, which predicts the convergence of warning patterns in order to gain the most protection from predators. However, despite this prediction, we can find great diversity of color patterns among Müllerian mimics such as butterflies in the neotropics. Furthermore, some species have evolved the ability to maintain multiple distinct warning patterns in single populations, a phenomenon known as polymorphic mimicry.

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The COVID-19 pandemic shut down undergraduate research programs across the United States. A group of 23 colleges, universities, and research institutes hosted remote undergraduate research programs in the life sciences during Summer 2020. Given the unprecedented offering of remote programs, we carried out a study to describe and evaluate them.

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The coffee berry borer (CBB) Hypothenemus hampei Ferrari is the most serious pest of coffee worldwide. Management of the CBB is extremely difficult because its entire life cycle occurs inside the fruit, where it is well protected. Knowing which life stages contribute most to population growth, would shed light on the population dynamics of this pest and help to improve CBB management programs.

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Host Manipulation Mechanisms of SARS-CoV-2.

Acta Biotheor

December 2021

Biology Department, University of Puerto Rico - Rio Piedras, San Juan, PR, USA.

Viruses are the simplest of pathogens, but possess sophisticated molecular mechanisms to manipulate host behavior, frequently utilizing molecular mimicry. Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) has been shown to bind to the host receptor neuropilin-1 in order to gain entry into the cell. To do this, the virus utilizes its spike protein polybasic cleavage site (PCS), which mimics the CendR motif of neuropilin-1's endogenous ligands.

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Language processing is cognitively demanding, requiring attentional resources to efficiently select and extract linguistic information as utterances unfold. Previous research has associated changes in pupil size with increased attentional effort. However, it is unknown whether the behavioral ecology of speakers may differentially affect engagement of attentional resources involved in conversation.

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When presented with the choice, females will often prefer to lay eggs on food containing a significant amount of alcohol. While, in some cases, this behavioral decision can provide a survival advantage to the developing larvae, it can also lead to developmental and cognitive problems. Alcohol consumption can affect executive functions, episodic memory, and other brain function capacities.

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Inferring the selective forces that orthologous genes underwent across different lineages can help us understand the evolutionary processes that have shaped their extant diversity and the phenotypes they underlie. The most widespread metric to estimate the selection regimes of coding genes-across sites and phylogenies-is the ratio of nonsynonymous to synonymous substitutions (d/d, also known as ). Nowadays, modern sequencing technologies and the large amount of already available sequence data allow the retrieval of thousands of orthologous genes across large numbers of species.

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Educational activities in biology teaching focused on model construction allow students to make the invisible evident. The development and integration of these pedagogical strategies in emerging sciences is essential and necessary in the classroom of noncollege academia. A two-component pedagogical activity was developed to expose high school students to the emerging disciplines of microbiomes and metagenomics.

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Understanding the molecular evolution of the SARS-CoV-2 virus as it continues to spread in communities around the globe is important for mitigation and future pandemic preparedness. Three-dimensional structures of SARS-CoV-2 proteins and those of other coronavirusess archived in the Protein Data Bank were used to analyze viral proteome evolution during the first 6 months of the COVID-19 pandemic. Analyses of spatial locations, chemical properties, and structural and energetic impacts of the observed amino acid changes in >48 000 viral isolates revealed how each one of 29 viral proteins have undergone amino acid changes.

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Honey bees utilize their circadian rhythms to accurately predict the time of day. This ability allows foragers to remember the specific timing of food availability and its location for several days. Previous studies have provided strong evidence toward light/dark cycles being the primary Zeitgeber for honey bees.

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Article Synopsis
  • Regeneration is vital for organisms to heal tissue and organs after injury or disease, and researchers are studying the molecular mechanisms behind this process.
  • The study investigates the Wnt/β-catenin signaling pathway's influence on intestinal regeneration in the sea cucumber Holothuria glaberrima, focusing on gene expression and the effects of β-catenin knockdown.
  • Results showed that while reducing β-catenin did not impact cell dedifferentiation or apoptosis, it significantly decreased cell proliferation, highlighting the importance of the Wnt/β-catenin pathway in regeneration.
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The hyperpolarization-activated cation current (I) is a determinant of intrinsic excitability in various cells, including dopaminergic neurons (DA) of the ventral tegmental area (VTA). In contrast to other cellular conductances, I is activated by hyperpolarization negative to -55 mV and activating I produces a time-dependent depolarizing current. Our laboratory demonstrated that cocaine sensitization, a chronic cocaine behavioral model, significantly reduces I amplitude in VTA DA neurons.

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This multicenter clinical study was aimed at conducting a targeted pharmacogenomic association analysis of residual on-clopidogrel platelet reactivity in 474 Caribbean Hispanic patients. Platelet reactivity was measured using the VerifyNow P2Y12 assay and clopidogrel resistance was defined as P2Y12 reaction units (PRUs) greater than or equal to 208. Genotyping was performed using the whole-genome Infinium MEGA BeadChip array.

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Article Synopsis
  • Sexually dimorphic development leads to significant physical differences in nature, with the gene doublesex (dsx) playing a key role in regulating these sex-specific traits.* -
  • Research on the Southern Dogface butterfly reveals a surprising duplication of the dsx gene that is linked to differences in ultraviolet (UV) wing patterns between males and females.* -
  • This duplicated gene may inhibit certain wing traits in females, indicating that dsx is crucial for controlling the development of secondary sexual characteristics through its molecular flexibility.*
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Vaccines represent preventative interventions amenable to immunogenetic prediction of how human variability will influence their safety and efficacy. The genetic polymorphism among individuals within any population can render possible that the immunity elicited by a vaccine is variable in length and strength. The same immune challenge (virus and/or vaccine) could provoke partial, complete or even failed protection for some individuals treated under the same conditions.

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Zika virus (ZIKV) infection has been associated with fetal abnormalities by compromising placental integrity, but the mechanisms by which this occurs are unknown. Flavivirus can deregulate the host proteome, especially extracellular matrix (ECM) proteins. We hypothesize that a deregulation of specific ECM proteins by ZIKV, affects placental integrity.

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Efforts directed at curtailing the bioavailability of intracellular iron could lead to the development of broad-spectrum anticancer drugs given the metal's role in cancer proliferation and metastasis. Human ribonucleotide reductase (RNR), the key enzyme responsible for synthesizing the building blocks of DNA replication and repair, depends on Fe binding at its R2 subunit to activate the catalytic R1 subunit. This work explores an intracellular iron chelator transmetalative approach to inhibit RNR using the titanium(IV) chemical transferrin mimetic (cTfm) compounds Ti(HBED) and Ti(Deferasirox).

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Cancer cells can develop resistance to anticancer drugs, thereby becoming tolerant to treatment through different mechanisms. The biological mechanisms leading to the generation of anticancer treatment resistance include alterations in transmembrane proteins, DNA damage and repair mechanisms, alterations in target molecules, and genetic responses, among others. The most common anti-cancer drugs reported to develop resistance to cancer cells include cisplatin, doxorubicin, paclitaxel, and fluorouracil.

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Onion-like carbon nanoparticles were synthesized from diamond nanoparticles to be used as the precursor for graphene oxide quantum dots. Onion-like carbon nanoparticles were exfoliated to produce two types of nanoparticles, graphene oxide quantum dots that showed size-dependent fluorescence and highly stable inner cores. Multicolor fluorescent quantum dots were obtained and characterized using different techniques.

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Heliconius butterflies: a window into the evolution and development of diversity.

Curr Opin Genet Dev

August 2021

Department of Biology, University of Puerto Rico-Rio Piedras, San Juan, Puerto Rico; Molecular Sciences and Research Center, University of Puerto Rico, San Juan, Puerto Rico. Electronic address:

Butterflies have become prominent models for studying the evolution and development of phenotypic variation. In Heliconius, extraordinary within species divergence and between species convergence in wing color patterns has driven decades of comparative genetic studies. However, connecting genetic patterns of diversification to the molecular mechanisms of adaptation has remained elusive.

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Mimicry is exhibited in multiple scales, ranging from molecular, to organismal, and then to human society. 'Batesian'-type mimicry entails a conflict of interest between sender and receiver, reflected in a deceptive mimic signal. 'Müllerian'-type mimicry occurs when there is perfect common interest between sender and receiver in a particular type of encounter, manifested by an honest co-mimic signal.

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Receptors are important pharmacological targets on cells. The Triggering Receptor Expressed on Myeloid Cells (TREM) - Like Transcript - 1 is an abundant, yet little understood, platelet receptor. It is a single Ig domain containing receptor isolated in the α-granules of resting platelets and brought to the platelet surface upon activation.

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Solubility Measurements and Correlation of MBQ-167 in Neat and Binary Solvent Mixtures.

J Chem Eng Data

January 2021

Crystallization Design Institute, Molecular Sciences Research Center, University of Puerto Rico, San Juan, Puerto Rico 00926, United States; Department of Pharmaceutical Sciences, University of Puerto Rico - Medical Sciences Campus, San Juan, Puerto Rico 00936, United States.

MBQ-167 is a novel, small-molecule dual inhibitor of Rac and Cdc42, small GTPases that are involved in cytoskeletal organization, cell cycle progression, and cell migration. In an mouse model, MBQ-167 has been shown to significantly reduce mammary tumor growth and metastasis and is currently undergoing preclinical studies for the treatment of metastatic cancer. To date, no solubility data have been reported for this compound.

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Tropical forests are the largest contributors to global emissions of carbon dioxide (CO) to the atmosphere via soil respiration ( ). As such, identifying the main controls on in tropical forests is essential for accurately projecting the consequences of ongoing and future global environmental changes to the global C cycle. We measured hourly in a secondary tropical moist forest in Puerto Rico over a 3-year period to (a) quantify the magnitude of and (b) identify the role of climatic, substrate, and nutrient controls on the seasonality of .

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