Search Results (171)

Microplastic pollution has become a global concern due to its widespread impacts on organisms and ecosystems. While there have been a few studies quantifying microplastics in inland areas of Puerto Rico, none, to our knowledge, have studied nearshore coastal surface waters. This study, therefore, presents the first assessment of microplastic concentrations and descriptions in the surface waters of La Parguera Natural Reserve, southwestern Puerto Rico. Using 333-micron plankton net trawls, we found low mean ± standard deviation microplastic concentrations of 0.02 ± 0.07 microplastic particles m⁻³ (95% confidence interval = 0.01 to 0.04 microplastic particles m⁻³). The most prevalent polymers were high-density polyethylene (48%) and polyethylene (32%), followed by polypropylene (11%) and polystyrene (7%). The most common colors were white (50%), blue (34%), black (8%), red (5%), and colorless (3%). Subsequently, the common structures found were fragments (78%), filaments (12%), films (8%), and fibers (2%). No clear coastal gradient or seasonal patterns were detected (p < 0.05), and mean concentrations were similar to previously surveyed oceanic waters from the Caribbean, suggesting coastal sources of marine microplastics were minimal compared to oceanic sources. This study provides a foundational understanding of microplastics in the coastal waters of La Parguera Natural Reserve and provides critical baseline data for detecting potential future changes in microplastic concentrations. Full article

Resource-constrained wearable systems often need to be able to execute signal processing and AI workloads. There are many trade-offs to consider for this type of application. This paper presents a lightweight convolution-aware soft processor for embedded signal-processing on resource-constrained wearable devices. This architecture represents a middle ground for signal-processing applications between dedicated accelerators and lightweight soft processors. The proposed architecture integrates a two-lane SIMD integer datapath with a split-stage IEEE-754 floating-point accumulation pipeline. The split-stage design enables overlap between multiplication, accumulation, and operand fetch, improving arithmetic utilization while maintaining low resource costs. The processor was implemented on the Artix-7-based Basys3 platform and evaluated using one-dimensional convolution workloads. The experimental results demonstrate a $6\times$ speedup over MicroBlaze-class soft processors while maintaining the same static power usage (0.073 W), and only requiring 44% higher dynamic power consumption. The architecture achieves this with significantly fewer FPGA resources than accelerator-based solutions such as DPU overlays. The proposed architecture provides a practical alternative for wearable and resource-constrained FPGA systems requiring deterministic convolution performance, demonstrating a balanced design point for embedded wearable platforms where software-defined flexibility and convolution acceleration are both required. Full article

Natural bioactive polysaccharides have been investigated for their ability to modulate antiviral immune responses. Polysaccharide peptide (PSP) from Coriolus versicolor previously restricted human immunodeficiency virus type 1 (HIV-1) entry into monocytic cells through a protein kinase R (PKR)-dependent cytoskeletal mechanism. However, its impact on antiviral signaling in adaptive cluster of differentiation 4 (CD4)+ T-cell models remains incompletely defined. Here, we evaluated concentration- and time-dependent effects of PSP (50–1000 µg/mL) in Jurkat T cells over 3 and 6 days. Cell viability was assessed by MTT, trypan blue exclusion, and viable cell density analysis. Immunoblotting and reverse transcription quantitative polymerase chain reaction (RT-qPCR) were performed to examine Toll-like receptor 4 (TLR4), nuclear factor kappa B (NF-κB), signal transducer and activator of transcription 1 and 2 (STAT1/STAT2), PKR, interferon gamma (IFN-γ), and cofilin-1 signaling. PSP did not induce cytotoxicity at any concentration. Instead, PSP promoted dose- and time-dependent upregulation of intracellular TLR4, PKR, phospho-PKR (Thr446), Cofilin-1, phospho-Cofilin-1 (Ser3), phospho-STAT1 (Tyr701), phospho-STAT2 (Tyr690), phospho-NF-κB (Ser536), and IFN-γ, with amplified responses at Day 6. These changes were paralleled by transcriptional induction of antiviral-associated genes. Collectively, PSP induces coordinated interferon (IFN)-associated and cytoskeletal regulatory signaling in Jurkat T cells without cytotoxicity, providing a mechanistic framework for future evaluation of viral permissiveness and antiviral responses in adaptive immune models. Full article

Enterococci are widely used indicators of fecal contamination because they originate in the gastrointestinal tracts of warm-blooded animals, and species-level identification can support source attribution. This study evaluated the temporal abundance and species composition of enterococci in Quebrada Mondongo, southwestern Puerto Rico, a stream influenced by wastewater treatment plant (WWTP) effluent and nonpoint-source inputs. Five sampling campaigns for species distribution and fourteen for population quantification were conducted over approximately one year at the WWTP effluent discharge and at upstream and downstream stations. Enterococci concentrations exceeded the regulatory threshold for surface waters. Among the confirmed isolates, E. faecium dominated upstream and in the effluent, occurring approximately twofold more frequently than E. faecalis. Downstream, E. faecalis increased in relative abundance, shifting the species ratio of E. faecium/E. faecalis from 2.3–3.2 to 0.89. E. casseliflavus was detected at low frequency, and E. gallinarum was not observed. Virulence-associated genes (esp, gelE) were identified in ~75% of E. faecalis isolates, consistent with enhanced environmental persistence. Although upstream and effluent patterns reflected a strong human fecal signal, the downstream enrichment of E. faecalis suggests additional secondary inputs and/or naturalization. This study provides empirical evidence of species shifts in a tropical stream, with an increase in E. faecalis downstream of a WWTP despite E. faecium dominance in the effluent highlighting the likely influence of other nonpoint fecal sources within the watershed. Overall, these results suggest that the WWTP effluent did not contribute substantially to enterococci concentrations nor significantly influence the species composition of enterococci downstream in Quebrada Mondongo, highlighting the likely influence of other nonpoint fecal sources within the watershed. Full article

The environmental persistence of β-lactam antibiotics represents a growing ecological concern, requiring materials capable of combined adsorption and catalytic degradation. Herein, pure ZnS and 1% Fe-doped ZnS nanoparticles were synthesized via microwave-assisted treatment and evaluated for the removal of ceftaroline fosamil from aqueous media. Transmission electron microscopy revealed quasi-spherical nanoparticles below 10 nm, while selected area electron diffraction confirmed a face-centered cubic structure retained after Fe incorporation. UV-Vis spectroscopy showed similar absorption edges (~316 nm), indicating negligible band-gap variation, whereas photoluminescence analysis demonstrated strong emission quenching in Fe-ZnS, indicating suppressed electron–hole recombination. Point-of-zero charge measurements (pH_PZC ≈ 4.6 for ZnS; 4.5 for Fe-ZnS) indicated negatively charged surfaces under circumneutral conditions, influencing interfacial interactions with the antibiotic. Adsorption experiments followed the Langmuir isotherm model, with Fe-ZnS exhibiting a higher maximum adsorption capacity (156 mg g⁻¹) compared to ZnS (115 mg g⁻¹). Under UV irradiation (302 nm), Fe-ZnS achieved near-complete degradation at a catalyst loading of 500 ppm. Liquid chromatography–mass spectrometry analysis revealed the transformation of ceftaroline fosamil (m/z 685.01) into ceftaroline (m/z 605.05) via phosphate group loss, followed by the formation of intermediate fragments at m/z 492.08 and 308.03, associated with cleavage of the thiadiazol-amine moiety and subsequent opening of the cephalosporin ring. After extended irradiation, these intermediates diminished, and a fragment at m/z 356.01 was detected, suggesting further breakdown through thioether bond cleavage. These results support a degradation pathway involving sequential dephosphorylation and fragmentation of the cephalosporin core. Overall, the enhanced performance of Fe-ZnS arises from the synergistic interplay between surface charge characteristics and dopant-modulated charge carrier dynamics, highlighting its potential for antibiotic remediation in aquatic environments. Full article

Despite the remarkable success of antiretroviral therapy (ART) in suppressing human immunodeficiency virus type 1 (HIV-1) replication, viral persistence remains a major barrier to cure. This persistence is sustained by heterogeneous cellular reservoirs in which viral expression is tightly regulated by host-dependent molecular mechanisms. Beyond the canonical cluster of differentiation 4 (CD4+) T-cell reservoirs, HIV-1 establishes long-lived infection in myeloid cells, glial populations within the central nervous system (CNS), and additional non-canonical cellular niches, each characterized by distinct transcriptional, epigenetic, and immune environments. In this review, we synthesize recent advances in understanding how HIV-1 expression, latency, and reactivation are shaped across diverse susceptible cell types. We highlight cell-type-specific mechanisms governing viral integration, chromatin organization, transcriptional elongation, innate immune sensing, host restriction factors, and cytoskeletal regulation. Particular emphasis is placed on how host signaling pathways and immune microenvironments contribute to reservoir stability and heterogeneity, complicating eradication strategies. We further discuss immunomodulatory approaches that seek to modulate viral expression without exacerbating immune activation. By integrating molecular, cellular, and immunological perspectives, this review provides a framework for understanding HIV-1 persistence as a context-dependent process and underscores the need for cell-type-tailored strategies in HIV cure research. Full article

This study considers temperature gradients over recent decades near Trujillo, Peru, (8.15 S, 78.95 W) using high-resolution data assimilation. Statistical analyses describe a steep gradient from the cool foggy coast to the warm coastal plains below the Andes. A cross-coast transect is analyzed for seasonal changes in maximum air temperature from SENAMHI station data interpolated with satellite infrared measurements. Weather forecasts aimed at the urban area show a cool bias at higher temperatures and often under-represent the landward increase of 5 °C/10 km, induced by wind-driven upwelling and turbulent heat flux. Morning fog-stratus tends to delay diurnal heating on the beachfront, whereas, a few kilometers inland, warming occurs due to the segregating effect of channeled long-shore winds. Although seasonality is limited near Trujillo, winter exhibits the greatest variance of maximum temperature due to fluctuations of cloud albedo. Regressions of temperature time series onto meteorological fields identify that a subtropical trough/ridge pattern leads to higher winter values due to weaker upwelling, warmer sea temperatures, and reduced fog-stratus. Long-term trends for increased sea/land gradients have implications for the adaptation to climate change. Full article

Background/Objectives: In Puerto Rico (PR), lung cancer mortality remains high because diagnoses frequently occur at advanced stages. Although low-dose computed tomography (LDCT) lowers lung cancer–specific mortality, this screening is difficult to operationalize locally due to high false-positive rates, radiology capacity constraints, payer limitations, and geographic barriers affecting rural populations. Methods: We performed a narrative review on the literature from 2001–2026 of established and emerging detection strategies—LDCT; serum biomarkers (CEA, CYFRA-21-1, NSE, ProGRP, SCC-Ag, HE4, Hp, TAAb); breath analysis (FeNO and VOCs); and liquid biopsy (ctDNAs/CTCs/miRNAs). We assessed technical performance, feasibility, and health-system fit in PR and then synthesized these findings into an implementable biomarker-first triage workflow for are. Results: Multiplex serum panels analyzed with machine learning outperform single markers and TAAb provide high specificity with biological lead time, supporting their use as a triage gateway before LDCT. Breathomics is also feasible at the point of care. Liquid biopsy has modest sensitivity in very-early disease yet provides molecular adjudication for indeterminate nodules. A stepwise pathway—expanded risk assessment, integrated multi-panel testing in primary care, LDCT reserved for biomarker-positive individuals, and liquid biopsy when imaging is inconclusive—can enrich pre-test probability, reduce unnecessary scans, align with capitation, and protect limited radiology capacity. Conclusions: An integrated, non-invasive, biomarker-first triage model offers a pragmatic, equitable route to earlier lung cancer detection in PR and resource stewardship, while reducing disparities. Full article

Background/Objectives: Puerto Rican Hispanic/Latino (PR H/L) men experience a heightened incidence and mortality rate of aggressive forms of prostate cancer. The underlying causes of this increased disease burden likely include a complex interplay of socio-economic and biological factors. This pilot study leveraged the first cancer tissue biobank at a Hispanic-Serving Institution (Puerto Rico BioBank) and aimed to provide an initial description of the genomic features of prostate cancer in 35 PR H/L men. Methods: Whole-exome and RNA sequencing were performed on prostate adenocarcinoma tumor samples to investigate the genomic features associated with prostate cancer. Results: Our analysis suggests that mutation profiles and gene expression pattern differences are observed in this population and may be associated with disease aggressiveness and progression. Notably, mutations in TP53 and TMPRSS2-ERG gene fusions, which are common in broader populations, were less prevalent in the PR H/L cohort. Conclusions: While this study contributes to the understanding of ethnicity-specific genetic factors in prostate cancer, underscoring the need for inclusive genomic studies, continued expansion to larger cohorts of patients under-represented in large genomic studies will be needed to more robustly characterize the full range of genomic features of prostate cancer. A broader understanding of the genomic features of prostate cancer in PR H/L men may lead to future opportunities for delivering more personalized prognoses and treatment options, helping to ensure that treatment advances and better outcomes are available to all patients. Full article

The 2x2 Demonstrator, a prototype for the Deep Underground Neutrino Experiment (DUNE) liquid argon (LAr) Near Detector, was exposed to the Neutrinos from the Main Injector (NuMI) neutrino beam at Fermi National Accelerator Laboratory (Fermilab). This detector is a prototype of a new modular design for a liquid argon time-projection chamber (LArTPC), comprising a two-by-two array of four modules, each further segmented into two optically isolated LArTPCs. The 2x2 Demonstrator features a number of pioneering technologies, including a low-profile resistive field shell to establish drift fields, native 3D ionization pixelated imaging, and a high-coverage dielectric light readout system. The 2.4-tonne active mass detector is flanked upstream and downstream by supplemental solid-scintillator tracking planes, repurposed from the MINERvA experiment, which track ionizing particles exiting the argon volume. The antineutrino beam data collected by the detector over a 4.5 day period in 2024 include over 30,000 neutrino interactions in the LAr active volume—the first neutrino interactions reported by a DUNE detector prototype. During its physics-quality run, the 2x2 Demonstrator operated at a nominal drift field of 500 V/cm and maintained good LAr purity, with a stable electron lifetime of approximately 1.25 ms. This paper describes the detector and supporting systems, summarizes the installation and commissioning, and presents the initial validation of collected NuMI beam and off-beam self-triggers. In addition, it highlights observed interactions in the detector volume, including candidate muon antineutrino events. Full article

Hyperglycemia is linked to a higher risk of diabetes, epilepsy, and seizures, which contribute to increased mortality. Previous research has shown that hyperglycemia impairs the function of the polyamine-dependent Kir4.1 channels in cultured astrocytes, and a similar effect was observed in male astrocytes from diabetic (db/db) mice. However, whether there are sex differences in this effect remains unclear. This study aims to compare Kir4.1 channel function in 10–12 week old brains of female db/db mice with that in males and non-diabetic heterozygous (db/+). We performed mRNA analyses, Western blotting (WB), glucose level measurements, and patch-clamp recordings from hippocampal astrocytes in brain slices to assess Kir4.1 channel activity in db/db and db/+ mice of both sexes. Our results showed increased glucose levels in diabetic db/db mice, especially in males, along with (1) reduced synthesis of Kir4.1 channel protein, (2) reduced membrane potential, (3) decreased Kir currents, and (4) compromised potassium uptake. Female diabetic astrocytes exhibited significantly lower barium-blocked Kir4.1 currents compared to diabetic males. Additionally, barium-insensitive currents (leakage currents) were upregulated in db/db mice, likely as a compensatory response to hyperglycemia. In conclusion, diabetes impairs astrocyte function by downregulating Kir4.1 channels, with a more pronounced effect in male diabetic mice. This impairment may increase seizure risk by affecting the ability of astrocytes to maintain extracellular ion balance. Full article

The production of quantum dots (QDs) has increased due to their wide variety of commercial products and applications. QDs can be dangerous in the environment because their small size can encourage their incorporation into living systems. In this project, ZnS and ZnSSe were synthesized under microwave irradiation, generating a water-stable nanomaterial. The bandgap energies calculated using the UV-Vis spectra were 3.81 and 3.86 eV for ZnS and ZnSSe QDs, respectively, indicating that the selenium worked as a dopant agent. The photoluminescence analysis shows narrow emission peaks, confirming a low size distribution, and the selenium doping generated a blue shift. The crystal size of both nanomaterials was around 7 nm. The cellular toxicity of these nanomaterials was evaluated using Chinese Hamster Ovary (CHO) Cells (a standard mammalian cell model). The results suggest that ZnS and ZnSSe QDs slightly affect the viability of CHO Cells, but Zn²⁺ decreases the viability at concentrations higher than 20 mg/L. The content of zinc inside cells (by ICP-OES) suggested that QDs can enter cells more easily than Zn²⁺. Therefore, the decrease in cell viability caused by Zn²⁺ outside the cells is likely due to its effect on cell membrane integrity, suggesting that these nanomaterials are less toxic than bulk materials. Full article

The increasing presence of pharmaceutical residues such as ibuprofen in aquatic environments represents a growing concern due to their persistence and limited biodegradability. In this study, selenium-doped tin oxide (SnO₂:Se) nanoparticles covered with glycerol were synthesized via a microwave-assisted method to evaluate their photocatalytic performance in the degradation of ibuprofen under ultraviolet (UV) and visible light. Optimal synthesis parameters were determined at pH 7.5–8.0 and 130 °C, yielding stable, dark-brown colloidal suspensions. HRTEM analysis revealed a coexistence of one-dimensional (1D) nanowires and zero-dimensional (0D) quantum dots, confirming nanoscale morphology with crystallite sizes between 8 and 100 nm. EDS analysis confirmed the presence of Sn, O, and trace Se (0.1 wt%), indicating Se incorporation as a dopant. UV–Vis spectroscopy showed strong absorption near 324 nm and slight band-gap narrowing in the Se-doped samples, suggesting enhanced visible-light responsiveness. Photocatalytic experiments demonstrated an ibuprofen degradation efficiency of ~60% under visible light and 80% under UV irradiation with aeration, compared to only 5% removal using commercial SnO₂. The enhanced performance was attributed to Se-induced band-gap modulation, effective charge-carrier separation, and singlet oxygen generation. Full article

Because antigenic drift primarily generates amino-acid changes in the membrane-distal hemagglutinin (HA) head, broadly neutralizing antibodies (bNAbs) are being developed to target conserved epitopes in the membrane-proximal stem. Mutations to HA2 residue A44, a buried residue beneath the central stem epitope, in 2009 H1N1 viruses have been shown to cause resistance to stem-binding bNAbs. Here, we introduced A44V and A44T mutations into A/Tennessee/1-560/2009 (TN09) and A/Puerto Rico/15/2018 (PR18) and investigated their effects in cell culture, mice, and ferrets. In both virus strains, the mutations decreased HA and virus stability and decreased bNAb binding and neutralization in vitro. The mutations reduced pathogenicity and lung replication in DBA/2J mice. Ferrets were inoculated with PR18 wild-type (WT) or A44V virus, and the A44V mutation reduced day-1 and peak nasal virus titers. Airborne transmission in the A44V group occurred only after genotypic reversion (HA2-V44A) or acquisition of a distal re-stabilizing mutation (HA2-I77M). Compared to WT, an engineered PR18 virus containing both HA2 mutations (A44V and I77M) had similar growth and pathogenicity in mice in addition to decreased binding and neutralization by bNAbs. Overall, this work provides insight into the role of HA stability during HA stem-epitope remodeling that results in virus resistance to stem-binding bNAbs. Full article

Objectives: Neural tube defects such as myelomeningocele (MMC) remain a significant public health concern despite prevention efforts. Public health measures have reduced the global MMC incidence, but socioeconomic disparities may limit their impact. Puerto Rico (PR) is a United States (US) territory; however, its socioeconomic landscape is vastly different, which may contribute to differences in MMC incidence. In this study, we aimed to compare the differences in MMC incidence and annual variability between PR and the US. Materials and Methods: Data on MMC incidence for the US was obtained from the Centers for Disease Control’s National Vital Statistics Reports, and data for PR from the Puerto Rico Birth Defects Surveillance and Prevention System. Annual percentage change (APC) was used to evaluate year-to-year variation, and multiple linear regression analysis was applied to compare incidence rates. Results: The mean annual MMC incidence in 1996–2020 was 4.88 per 10,000 live births in PR (SD = 1.86), and 1.78 (SD = 0.35) in the US, with an estimated mean difference of 3.11 (p < 0.001). APCs during this period varied significantly, ranging from +200% to −63%. A subgroup analysis after folic acid fortification efforts in PR (1999–2020) showed a persistently elevated incidence in PR (mean = 4.41, SD = 1.33) vs. US (mean = 1.67, SD = 0.25), with an estimated mean difference of 2.72 (p < 0.001). Conclusions: Despite folic acid fortification and public health interventions, MMC incidence in PR remains higher and more variable. These findings underscore the need for improved disease reporting and targeted, region-specific preventive strategies. Full article