Splitting light pollution: Wavelength effects on the activity of two sandy beach species.

Artificial Light at Night (ALAN) threatens to disrupt most natural habitats and species, including those in coastal settings, where a growing number of studies have identified ALAN impacts. A careful examination of the light properties behind those impacts is important to better understand and manage the effects of this stressor. This study focused on ALAN monochromatic wavelengths and examined which types of light spectra altered the natural activity of two prominent coastal species from the Pacific southeast: the talitroid amphipod Orchestoidea tuberculata and the oniscoid isopod Tylos spinulosus. We compared the natural daylight/night activity of these organisms with the one they exhibit when exposed to five different ALAN wavelengths: lights in the violet, blue, green, amber, and red spectra. Our working hypothesis was that ALAN alters these species' activity at night, but the magnitude of such impact differs depending on light wavelengths. Measurements of activity over 24 h cycles for five consecutive days and in three separate experiments confirmed a natural circadian activity pattern in both species, with strong activity at night (∼90% of probability) and barely any activity during daylight. However, when exposed to ALAN, activity declined significantly in both species under all light wavelengths. Interestingly, amphipods exhibited moderate activity (∼40% of probability) when exposed to red lights at night, whereas isopods shifted some of their activity to daylight hours in two of the experiments when exposed to blue or amber lights, suggesting a possible alteration in this species circadian rhythm. Altogether, our results were consistent with our working hypothesis, and suggest that ALAN reduces night activity, and some wavelengths have differential effects on each species. Differences between amphipods and isopods are likely related to their distinct adaptations to natural low-light habitat conditions, and therefore distinct sensitivity to ALAN.

Field experimental evidence of sandy beach community changes in response to artificial light at night (ALAN).

Artificial light at night (ALAN) is a pervasive but still under-recognized driver of global change. In coastal settings, a large majority of the studies assessing ALAN impacts has focused on individual species, even though it is unclear whether results gathered from single species can be used to predict community-wide responses. Similarly, these studies often treat species as single life-stage entities, ignoring the variation associated with distinct life stages. This study addresses both limitations by focusing on the effects of ALAN on a sandy beach community consisting of species with distinct early- and late-life stages. Our hypothesis was that ALAN alters community structure and these changes are mediated by individual species and also by their ontogenetic stages. A field experiment was conducted in a sandy beach of north-central Chile using an artificial LED system. Samples were collected at different night hours (8-levels in total) across the intertidal (9-levels) over several days in November and January (austral spring and summer seasons). The abundance of adults of all species was significantly lower in ALAN treatments. Early stages of isopods showed the same pattern, but the opposite was observed for the early stages of the other two species. Clear differences were detected in the zonation of these species during natural darkness versus those exposed to ALAN, with some adult-juvenile differences in this response. These results support our hypothesis and document a series of changes affecting differentially both early and late life stages of these species, and ultimately, the structure of the entire community. Although the effects described correspond to short-term responses, more persistent effects are likely to occur if ALAN sources become established as permanent features in sandy beaches. The worldwide growth of ALAN suggests that the scope of its effect will continue to grow and represents a concern for sandy beach systems.

Metabolic rate allometry in intertidal mussels across environmental gradients: The role of coastal carbonate system parameters in mediating the effects of latitude and temperature.

We assess the role of direct and indirect effects of coastal environmental drivers (including the parameters of the carbonate system) on energy expenditure (MR) and body mass (M) of the intertidal mussel, Perumytilus purpuratus, across 10 populations distributed over 2800 km along the Southern Eastern Pacific (SEP) coast. We find biogeographic and local variation in carbonate system variables mediates the effects of latitude and temperature on metabolic rate allometry along the SEP coast. Also, the fitted Piecewise Structural Equation models (PSEM) have greater predictive ability (conditional R2 = 0.95) relative to the allometric scaling model (R2 = 0.35). The largest standardized coefficients for MR and M were determined by the influence of temperature and latitude, followed by pCO2, pH, total alkalinity, and salinity. Thus, physiological diversity of P. purpuratus along the SEP coast emerges as the result of direct and indirect effects of biogeographic and local environmental variables.

A paleoepidemiological approach to the challenging differential diagnosis of an isolated 1500-year-old anomalous molar from Panamá.

OBJECTIVE: This study seeks to quantify the presence and prevalence of specific genetic and infectious diseases in the pre-Colombian Panamanian population and uses these data to consider the plausibility of these diseases as causative factors in the development of an abnormal supernumerary cusp morphology in a 1500-year-old isolated molar recovered from Cerro Juan Díaz (Los Santos, Panama). MATERIALS: 267 individuals from pre-Columbian sites throughout Panama. METHODS: The anomalous tooth was analyzed through macroscopic, odontometric, and radiographic means. Tentative differential diagnosis was performed using inferences from paleopathological features of the broader regional population. RESULTS: The regional sample showed evidence of treponemal infection and developmental anomalies in 10.1% and 10.9% of individuals, respectively. CONCLUSIONS: While not able to rule out three potential genetic conditions, more evidence was found to support the differential diagnosis of congenital syphilis as the causative agent leading to the development of abnormal supernumerary cusps in the isolated molar. SIGNIFICANCE: This study demonstrates how characterizing disease experience in the population can assist in differential diagnoses at the individual level and cautions against the assumption that any one lesion in isolation is unique to only one specific pathological condition. LIMITATIONS: The timing discrepancy between clinical descriptions of congenital syphilis and genetic disorders, lack of knowledge on pathophysiological mechanisms of the former, poor preservation of Treponema pathogen ancient DNA, and deficiencies in modern public health data from Panama limit the differential diagnosis. SUGGESTIONS FOR FURTHER RESEARCH: Inclusion and serious contemplation of genetic diseases in paleopathological differential diagnoses is necessary.

Morphological, physiological and behavioral responses of an intertidal snail, Acanthina monodon (Pallas), to projected ocean acidification and cooling water conditions in upwelling ecosystems.

Ocean acidification (OA) is expected to rise towards the end of the 21st century altering the life history traits in marine organisms. Upwelling systems will not escape OA, but unlike other areas of the ocean, cooling effects are expected to intensify in these systems. Regardless, studies evaluating the combined effects of OA and cooling remain scarce. We addressed this gap using a mesocosm system, where we exposed juveniles of the intertidal muricid snail Acanthina monodon to current and projected pCO2 (500 vs. 1500 ppm) and temperature (15 vs. 10 °C) from the southeast Pacific upwelling system. After 9 weeks of experimental exposure to those conditions, we conducted three estimations of growth (wet weight, shell length and shell peristomal length), in addition to measuring calcification, metabolic and feeding rates and the ability of these organisms to return to the normal upright position after being overturned (self-righting). Growth, feeding and calcification rates increased in projected cooling conditions (10 °C) but were unaffected by pCO2 or the interaction between pCO2 and temperature. Instead, metabolic rates were driven by pCO2, but a significant interaction with temperature suggests that in cooler conditions, metabolic rates will increase when associated with high pCO2 levels. Snail self-righting times were not affected across treatments. These results suggest that colder temperatures projected for this area would drive this species growth, feeding and calcification, and consequently, some of its population biology and productivity. However, the snails may need to compensate for the increase in metabolic rates under the effects of ocean acidification. Although A. monodon ability to adjust to individual or combined stressors will likely account for some of the changes described here, our results point to a complex dynamic to take place in intertidal habitats associated with upwelling systems.

Ocean acidification alters anti-predator responses in a competitive dominant intertidal mussel.

Widespread intertidal mussels are exposed to a variety of natural and anthropogenic stressors. Even so, our understanding of the combined influence of stressors such as predation risk and ocean acidification (OA) on these species remains limited. This study examined the response of the purple mussel (Perumytilus purpuratus), a species distributed along Pacific southeastern rocky shores, to the effects of predation risk and OA. Using a laboratory 2 × 2 cross design, purple mussels were either devoid or exposed to predator cues from the muricid snail Acanthina monodon, while simultaneously exposing them to current (500 ppm) or projected OA conditions (1500 ppm). The response of purple mussels to these factors was assessed using growth, calcification, clearance, and metabolic rates, in addition to byssus production. After 60 d, the presence of predator cues reduced mussel growth in width and length, and in the latter case, OA enhanced this response making the effects of predator cues more severe. Calcification rates were driven by the interaction between the two stressors, whereas clearance rates increased only in response to OA, likely explaining some of the growth results. Mussel byssus production also increased with pCO2 but interacted with predation risk: in the absence of predator cues, byssus production increased with OA. These results suggest that projected levels of OA may alter and in some cases prevail over the natural response of purple mussels to predation risk. Considering the role played by this mussel as a dominant competitor and ecosystem engineer in rocky shores, these results have community-wide implications.

Weaving Mitochondrial DNA and Y-Chromosome Variation in the Panamanian Genetic Canvas.

The Isthmus of Panama was a crossroads between North and South America during the continent's first peopling (and subsequent movements) also playing a pivotal role during European colonization and the African slave trade. Previous analyses of uniparental systems revealed significant sex biases in the genetic history of Panamanians, as testified by the high proportions of Indigenous and sub-Saharan mitochondrial DNAs (mtDNAs) and by the prevalence of Western European/northern African Y chromosomes. Those studies were conducted on the general population without considering any self-reported ethnic affiliations. Here, we compared the mtDNA and Y-chromosome lineages of a new sample collection from 431 individuals (301 males and 130 females) belonging to either the general population, mixed groups, or one of five Indigenous groups currently living in Panama. We found different proportions of paternal and maternal lineages in the Indigenous groups testifying to pre-contact demographic events and genetic inputs (some dated to Pleistocene times) that created genetic structure. Then, while the local mitochondrial gene pool was marginally involved in post-contact admixtures, the Indigenous Y chromosomes were differentially replaced, mostly by lineages of western Eurasian origin. Finally, our new estimates of the sub-Saharan contribution, on a more accurately defined general population, reduce an apparent divergence between genetic and historical data.

An isthmus of isolation: The likely elevated prevalence of genetic disease in ancient Panama and implications for considering rare diseases in paleopathology.

OBJECTIVE: This study considers the evidence for elevated frequencies of "rare" diseases in ancient Panama. Indications of population isolation by multidisciplinary sources allow for the possibility that rare inherited conditions may have been maintained at relatively high prevalences in the region due to gene flow restriction. MATERIALS: A sample of 267 skeletal human remains with diverse demographical characteristics from Pre-Columbian archaeological sites throughout Panama. METHODS: Remains were analyzed macroscopically and hard tissue developmental anomalies were documented. RESULTS: Frequencies of developmental anomalies and hard tissue changes consistent with specific rare genetic diseases, such as osteogenesis imperfecta, on the comparatively few human remains recovered from pre-Columbian archaeological sites are elevated as compared with global averages. CONCLUSIONS: The paleopathological evidence is concordant with a scenario of isolation in Pre-Columbian times and with an increased presence of genetic disorders in the population. SIGNIFICANCE: This study advocates for the special consideration of rare diseases by paleopathologists in regions where populations may have experienced prolonged geographical or social isolation in the past. LIMITATIONS: A dearth of local modern epidemiological data and low sample sizes of preserved human remains in certain regions of the country limited the possibilities of spatiotemporal comparisons of rare disease prevalence. SUGGESTIONS FOR FURTHER RESEARCH: Further scrutiny of developmental anomalies of genetic origin on ancient Panamanian remains and biomolecular testing of remains for specific disorders should be pursued to confirm the findings of this study.

Cold-water diving in the tropics? External auditory exostoses among the pre-Columbian inhabitants of Panama.

OBJECTIVES: The appearance of external auditory exostoses archaeologically has been attributed to aquatic activities in middle latitudes. However, recent clinical research implicates low sea surface temperatures, especially below a threshold of 19°C, as a stronger predictor of ear exostosis development than latitude. Here, we examine the frequency of external auditory exostoses in human remains from nine pre-Columbian archaeological sites in Panama, representing individuals from a warm, tropical region. MATERIALS AND METHODS: External auditory exostoses were recorded as present when an abnormal bony growth was observed macroscopically within the ear canal. The presence of exostoses was compared by right and left side, geographical region, sex, and degree of stenosis. RESULTS: A total of 125 adult individuals made up the observable sample analyzed in this study. Exostoses were observed in seven males and one female. All individuals affected by this pathology were excavated from mortuary contexts along the Gulf of Panama-a region characterized by intense cold water upwelling in the dry season. DISCUSSION: This study suggests that external auditory exostoses in pre-Columbian Panama affected individuals involved in habitual aquatic activities in the cold, upwelled waters of the Gulf of Panama. These activities appear to be almost exclusively dominated by male individuals. Ethnohistorical and archaeological records point to marine shell resource acquisition by deep-water diving as the activity driving exostosis development in pre-Columbian Panama.

A probable primary malignant bone tumor in a pre-Columbian human humerus from Cerro Brujo, Bocas del Toro, Panamá.

We present a rare case of primary bone cancer principally affecting the right humerus of a skeleton from the pre-Columbian site of Cerro Brujo (1265-1380 CE) in Bocas del Toro, on the Caribbean coast of Panamá, excavated in the early 1970s. The humerus contains a dense, calcified sclerotic mass with associated lytic lesions localized around the midshaft of the diaphysis. Evidence of systemic inflammation and anemia, likely caused by the cancer, are visible in the form of severe porotic hyperostosis of the cranial vault and bilateral periosteal reactions in the tibiae. Differential diagnosis and future probes of the tumor are discussed. A tooth from the individual yielded a radiocarbon date 150 years later than those of the domestic occupation at the site. Given that it was the only formal burial recovered from the site, and as the individual had such a visible, painful, and rare pathology, this likely constitutes a ritual burial.

The skeletal manifestation of malaria: An epidemiological approach using documented skeletal collections.

OBJECTIVES: Recent studies in paleopathology have shown promise in associating some skeletal lesions with malarial infection. However, malaria's skeletal manifestation has never been confirmed using a large clinical reference sample from an endemic area for malaria with known individual causes of death. MATERIALS AND METHODS: To pinpoint evidence of malaria infection on ancient skeletal remains, this study uses an epidemiological approach to compare skeletal lesions in a modern reference sample of 98 individuals from Uganda, where malaria is holoendemic, to a similar modern sample of 106 individuals from a malaria-free area. RESULTS: Five porous skeletal lesions are identified that appear more frequently in the endemic area population, especially in anemic individuals. These appear on the cranium, vertebral column, and humeral and femoral necks. Periostitis also associates strongly with individuals in the endemic population; however, linear enamel hypoplasias show an inverse association. The identified lesions are tested for their association with each other, and then tested individually for their diagnostic power through measures of sensitivity and specificity. A diagnostic outcome algorithm is formed from the remaining skeletal lesions and their inter-lesion associations. DISCUSSION: Several etiological explanations for the characteristic malarial skeletal lesions are explored, including severe malarial anemia, an imbalance in bone remodeling, and extramedullary erythropoiesis. The importance of careful differential diagnoses between other infectious and noninfectious causes of these lesions is discussed, including the potential for coinfection of malaria with other infectious diseases. The findings of this study are pivotal in establishing diagnostic criteria by which we can identify the prevalence and impact of malaria on past populations.

Breast Cancer-Specific miR Signature Unique to Extracellular Vesicles Includes "microRNA-like" tRNA Fragments.

UNLABELLED: Extracellular vesicles (EV), including exosomes and shed vesicles, have been implicated in intercellular communication; however, their biomarker potential is less clear. Therefore, EVs derived from MCF7 and MCF10A cells were analyzed to identify unique miRNA (miR) profiles that distinguish their origin. One characteristic common to the miR profiles of MCF7 EVs and their parent cells is the high abundance of miR-21, let-7a, miR-100, and miR-125b, and low levels of miR-205. A second characteristic is the high abundance of "miRNA-like" tRNA fragments, which is unique to the MCF7 EVs, and is not found in comparing the cellular profiles. In addition, correlations were examined in the MCF7 cellular expression levels of these five miRs and two tRNA-derived miRNAs, miR-720 and miR-1274b, and compared with the correlations in MCF7 EV levels. Interestingly, correlations in the cellular expression of miR-125b, miR-100, and let-7a are mirrored in the EVs. In contrast, correlations in tRNA-derived miRNA levels are found only in the EVs. The findings suggest that EV miR clusters can be defined based on functional miR interactions related to correlated cellular expression levels or physical miR interactions, for example, aggregation due to comparable binding affinities to common targets. IMPLICATIONS: These results point to using high levels of tRNA-derived small RNA fragments in combination with known miR signatures of tumors to distinguish tumor-derived EVs in circulation from EVs derived from other cell sources. Such biomarkers would be unique to the EVs where high abundances of tRNA fragments are amplified with respect to their cellular levels.

Cribra orbitalia in the ancient Nile Valley and its connection to malaria.

Cribra orbitalia is a common skeletal lesion found on ancient human remains excavated from the Nile Valley. Recent etiological research implicates hemolytic anemia as a main factor leading to the formation of cribra orbitalia. Further, an association between the hemolytic anemia caused by malaria and cribra orbitalia has been demonstrated. The presence of malaria in the ancient Nile Valley has been verified directly through genetic and immunologic studies of Egyptian mummies, but its prevalence and spread remain unknown. As some models have pointed to the Nile Valley as the pathway of malarial dispersion during the Egyptian Dynastic period, variability in cribra orbitalia rates should provide a way to track the disease spread. This study surveyed cribra orbitalia frequencies at 29 ancient Nile Valley sites, representing 4760 individuals ranging from prehistoric to Christian periods and situated between the 3rd Cataract and Nile Delta. Results showed high cribra orbitalia rates, with an overall mean of 42.8% of the total population affected. Over time and space, the data showed no significant correlation, suggesting high levels of anemia affected individuals in the Nile Valley equally from late pre-dynastic to Christian periods. These findings suggest widespread endemic malaria in the Nile Valley before Dynastic Egypt.

Identification of conserved and HLA promiscuous DENV3 T-cell epitopes.

Anti-dengue T-cell responses have been implicated in both protection and immunopathology. However, most of the T-cell studies for dengue include few epitopes, with limited knowledge of their inter-serotype variation and the breadth of their human leukocyte antigen (HLA) affinity. In order to expand our knowledge of HLA-restricted dengue epitopes, we screened T-cell responses against 477 overlapping peptides derived from structural and non-structural proteins of the dengue virus serotype 3 (DENV3) by use of HLA class I and II transgenic mice (TgM): A2, A24, B7, DR2, DR3 and DR4. TgM were inoculated with peptides pools and the T-cell immunogenic peptides were identified by ELISPOT. Nine HLA class I and 97 HLA class II novel DENV3 epitopes were identified based on immunogenicity in TgM and their HLA affinity was further confirmed by binding assays analysis. A subset of these epitopes activated memory T-cells from DENV3 immune volunteers and was also capable of priming naïve T-cells, ex vivo, from dengue IgG negative individuals. Analysis of inter- and intra-serotype variation of such an epitope (A02-restricted) allowed us to identify altered peptide ligands not only in DENV3 but also in other DENV serotypes. These studies also characterized the HLA promiscuity of 23 HLA class II epitopes bearing highly conserved sequences, six of which could bind to more than 10 different HLA molecules representing a large percentage of the global population. These epitope data are invaluable to investigate the role of T-cells in dengue immunity/pathogenesis and vaccine design.

Encapsulation of hemoglobin inside liposomes surface conjugated with poly(ethylene glycol) attenuates their reactions with gaseous ligands and regulates nitric oxide dependent vasodilation.

Acellular hemoglobin (Hb)-based O2 carriers (HBOCs) are being investigated as red blood cell (RBC) substitutes for use in transfusion medicine. However, commercial acellular HBOCs elicit both vasoconstriction and systemic hypertension which hampers their clinical use. In this study, it is hypothesized that encapsulation of Hb inside the aqueous core of liposomes should regulate the rates of NO dioxygenation and O2 release, which should in turn regulate its vasoactivity. To test this hypothesis, poly(ethylene glycol) (PEG) conjugated liposome-encapsulated Hb (PEG-LEHs) dispersions were prepared using human and bovine Hb. In this study, the rate constants for O2 dissociation, CO association, and NO dioxygenation were measured for free Hb and PEG-LEH dispersions using stopped-flow UV-visible spectroscopy, while vasoactivity was assessed in rat aortic ring strips using both endogenous and exogenous sources of NO. It was observed that PEG-LEH dispersions had lower O2 release and NO dioxygenation rate constants compared with acellular Hbs. However, no difference was observed in the CO association rate constants between free Hb and PEG-LEH dispersions. Furthermore, it was observed that Hb encapsulation inside vesicles prevented Hb dependent inhibition of NO-mediated vasodilation. In addition, the magnitude of the vasoconstrictive effects of Hb and PEG-LEH dispersions correlated with their respective rates of NO dioxygenation and O2 release. Overall, this study emphasizes the pivotal role Hb encapsulation plays in regulating gaseous ligand binding/release kinetics and the vasoactivity of Hb.