Emerging arboviruses in Harris County, Texas

Harris County, which includes Houston, Texas, is an endemic and epidemic area for two viruses transmitted by arthropods (arboviruses). These viruses are maintained in cycles involving mosquitoes and wild birds, and transmission to humans is accidental. The majority of human infections is asymptomatic or may result in a flu-like syndrome. However, some infections can result in meningitis or encephalitis. These neuroinvasive infections may cause death, and those who survive may experience serious neurological complications requiring costly and lengthy medical care. The most important arboviruses in terms of morbidity are St. Louis encephalitis (SLEV) and West Nile (WNV) viruses. In fact, Harris County reports more SLEV encephalitis cases than any other county in the U.S. Most arboviral human cases occur from July through September, when mosquitoes are most active. Those at risk for encephalitis and death are the elderly and those with a history of hypertension or immunosuppresion. There is no specific treatment and no human vaccines are commercially available in the U.S. The approach for control of arboviruses in Harris County during epidemics is multidisciplinary and executed by several agencies. It includes surveillance, vector control, and educational messages for the population. Prevention of outbreaks consists of elimination of the vector and its breeding grounds, and practicing personal protective measures to prevent exposure to mosquitoes. ^ Current findings indicate that mosquito-borne viruses other than SLEV and WNV could pose an additional threat for the population. Eastern equine encephalitis virus (EEEV) activity has been detected in dogs and sentinel chickens in Houston and surrounding areas. Several serotypes of dengue virus have caused recent outbreaks in south Texas, and some locally-acquired cases have been detected in Houston. Since the clinical presentation of all arboviruses that cause encephalitis is very similar, and current surveillance is focused on detecting SLEV and WNV, there is a possibility that other arboviruses could be present in the area but are not being detected. Additionally, Harris County's ample annual rainfall and flooding problems, warm weather, multiple mosquito species, local and migrating birds that are susceptible to arboviral infection, and a constant flow of goods and travelers from many parts of the world could favor the emergence or re-emergence of other arboviruses. ^ The aims of this project were to determine if other arboviruses were circulating in the county, to assess the knowledge and attitudes about mosquito-borne viruses in a sample of the population, and to conduct an analysis of the initial WNV epidemic in Harris County. Through the retrospective analysis of clinical specimens collected during the 2002-2005 epidemic seasons, serologic evidence of dengue infection was detected suggesting the possibility that this virus may be co-circulating with SLEV and WNV. A cross-sectional survey revealed high awareness about arboviruses but not a consistent use of protective measures to avoid mosquitoes. The third component for this project included a retrospective review and geographical analysis of the 2002 WNV epidemic. ^ Overall, this study documented valuable information about the dengue virus, a potentially emerging arbovirus in Texas, revealed the need for more educational preventative programs, reinforced the value of mosquito and avian surveillance, and indicated the importance of continuing to investigate the factors that contribute to the development of outbreaks. ^

Pancreatic cancer deaths in Texas veterans

Background/objective. Several studies have found an increased risk of pancreatic cancer in veterans deployed to Vietnam during the Vietnam War. Diabetes, a known risk factor for pancreatic cancer, has been designated as a service-connected illness in deployed Vietnam veterans. The majority of Vietnam veterans, now between the ages of 55 to 65, have not yet reached the ages of pancreatic cancer’s greatest prevalence, ages 65 to 79. This case-control study utilized 1998 electronic Texas death certificate data for white, black and Hispanic men to explore the question of whether military service was a risk factor for deaths due to pancreatic cancer among men who died in 1998.^ Methods. The primary study included men born between 1927 and 1953, and was a matched case-control study with two control groups; 431 pancreatic cancer cases were birth-year and race-matched one case to two non-neoplastic death controls and, for the second control group, were matched 1:1 with 431 accidental death controls. The exposure was military service, recorded as “yes”, “no” or “unknown” on the death certificate. Conditional logistic regression was used for the data analysis. Logistic regression was used in two additional unmatched analyses to examine the same exposure, military service, within different birth cohorts, again using pancreatic cancer cases with non-neoplastic and accidental death controls.^ Results. For pancreatic cancer cases matched to non-neoplastic controls, the association with military service showed an elevated odds ratio (OR) of 1.40 (95% confidence interval [CI] 1.10-1.79); matched to accidental death controls, a similar association with military service was detected [OR=1.40 (95% CI 1.04-1.89)]. The association was not seen in all time periods and was greatest for those within a birth cohort specific for Vietnam Era service. For men born between 1946 and 1950, OR=1.90 (95% CI 1.03-3.50) for comparison with non-neoplastic controls and OR=1.91 (95% CI 0.9995-3.64) for accidental death controls. ^ Conclusion. In Texas, for men aged 44-71, who died in 1998, military service was associated with an approximately 40% increased risk for pancreatic cancer. For men ages 48-52, military service was associated with an approximately 90% increased risk for pancreatic cancer.^

The Relationship of Provincial Economic Level and Child Injury Mortality in Thailand: A Cross-Sectional Analysis in a Middle Income Country

The objective of this cross-sectional study was to examine the relationship of provincial economic development indices with incidences of child injury mortality in Thailand from 1999 - 2001. All injury deaths among children age 1-14 years were included. The independent variables included gross provincial product per capita (GPP/c), poverty and inequality indices, material and social deprivation indices, population in rural/ urban areas, and migration. Due to multicollinearity of such variables, the 76 provinces were categorized by GPP/c quartile, and means of overall injury, drowning, and transport-related mortality rates were compared among quartile groups. Spearman’s rho correlation between GPP/c and injury mortality rates was also performed. Finally, factor analysis was employed to create a set of factors to be treated as uncorrelated variables and stepwise multiple regression was carried out for the effects of the factors on injury mortality rates. A significant direct relationship was observed between GPP/c and overall injury mortality among children age 1-4 years, and 10-14 year-olds of both genders. Drowning was the main cause of this relationship among children age 1-4 years, and transport-related injury was the principle cause among children age 10-14 years. Conversely, provinces with lower GPP/c experienced higher injury mortality rates among school-age children 5-9 years old for both genders, mostly due to drowning. Factor analysis, and multiple regression results confirmed the relationships between economic development and injury mortality rates. These findings revealed that economic development had an adverse impact on injury-related mortality among children 1 to 4 and 10 to14 in Thailand.

Chronostratigraphic framework at sites GeoB14403 and GeoB14414 from the Gela Basin, Sicily Channel

A multi-proxy chronological framework along with sequence-stratigraphic interpretations unveils composite Milankovitch cyclicity in the sedimentary records of the Last GlacialeInterglacial cycle at NE Gela Basin on the Sicilian continental margin. Chronostratigraphic data (including foraminifera-based eco-biostratigraphy and d18O records, tephrochronological markers and 14C AMS radiometric datings) was derived from the shallow-shelf drill sites GeoB14403 (54.6 m recovery) and GeoB14414 (27.5 m), collected with both gravity and drilled MeBo cores in 193 m and 146 m water depth, respectively. The recovered intervals record Marine Isotope Stages and Substages (MIS) from MIS 5 to MIS 1, thus comprising major stratigraphic parts of the progradational deposits that form the last 100-ka depositional sequence. Calibration of shelf sedimentary units with borehole stratigraphies indicates the impact of higher-frequency (20-ka) sea level cycles punctuating this 100-ka cycle. This becomes most evident in the alternation of thick interstadial highstand (HST) wedges and thinner glacial forced-regression (FSST) units mirroring seaward shifts in coastal progradation. Albeit their relatively short-lived depositional phase, these subordinate HST units form the bulk of the 100-ka depositional sequence. Two mechanisms are proposed that likely account for enhanced sediment accumulation ratios (SAR) of up to 200 cm/ka during these intervals: (1) intensified activity of deep and intermediate Levantine Intermediate Water (LIW) associated to the drowning of Mediterranean shelves, and (2) amplified sediment flux along the flooded shelf in response to hyperpycnal plumes that generate through extreme precipitation events during overall arid conditions. Equally, the latter mechanism is thought to be at the origin of undulated features resolved in the acoustic records of MIS 5 Interstadials, which bear a striking resemblance to modern equivalents forming on late-Holocene prodeltas of other Mediterranean shallow-shelf settings.

Composition of chromian diopside megacryst in DSDP Leg 37 basalts (Table 2, 3)

Refractory megacrysts of olivine, plagioclase, chromian diopside and Cr-Al spinel, which were not in equilibrium with the host oceanic tholeiite on eruption, are present in samples from several dredge sites and DSDP drill sites in the Atlantic and Pacific Oceans. They have multiple origins: (1) cognate or accidental mantle fragments; (2) relict fragments from fractional crystallization of parental liquids considerably more primitive than oceanic tholeiite; and most commonly (3) the fractional crystallization products of such liquids mixed with oceanic tholeiite magma. Melt inclusions in chrome-spinel phenocrysts provide evidence for this postulated Mg- and Ca-rich magma which has counterparts in the Scottish Tertiary Province and in west Greenland.

Stable isotope composition of carbonate components of Rhaetian shallow-water limestones of the Wombat Plateau

Stable oxygen- and carbon-isotope ratios of Rhaetian (upper Triassic) limestone samples from the Wombat Plateau, northwest Australia, were measured to explore possible diagenetic pathways that the material underwent after deposition in a shallow-water environment, before plateau submergence in the Early Cretaceous. Host sediment isotopic values cluster near typical marine carbonate values (d18O ranging from -2.57 per mil to +1.78 per mil and d13C, from +2.45 per mil to +4.01 per mil). Isotopic values of equant clear calcite lining or filling rock pores also plot in the field of marine cements (d18O = +1.59 per mil to -2.24 per mil and d13C = +4.25 per mil to +2.57 per mil), while isotopic values for neomorphic calcites replacing skeletal (megalodontid shell) carbonate material show a wider scatter of oxygen and carbon values, d18O ranging from +2.73 per milo to -6.2 per mil and d13C, from +5.04 per mil to +1.22 per mil. Selective dissolution of metastable carbonate phases (aragonite?) and neomorphic replacement of skeletal material probably occurred in a meteoric phreatic environment, although replacement products (inclusion-rich microspar, clear neomorphic spar, etc.) retained the original marine isotopic signature because transformation probably occurred in a closed system dominated by the composition of the dissolving phases (high rock/water ratio). The precipitation of late-stage equant (low-Mg?) calcite cement in the pores occurred in the presence of normal marine waters, probably in a deep-water environment, after plateau drowning. Covariance of d18O and d13C toward negative values indeed suggests influence of meteorically modified fluids. However, none of the samples shows negative carbon values, excluding the persistence of organic-rich soils on subaerial karstic surfaces (Caribbean-style diagenesis). Petrographical and geochemical data are consistent with the sedimentological evidence of plateau drowning in post-Rhaetian times and with a submarine origin of the >70-m.y.-long Jurassic hiatus.

Geological investigations on sediment core MD07-3128

Glacial millennial-scale paleoceanographic changes in the Southeast Pacific and the adjacent Southern Ocean are poorly known due to the scarcity of well-dated and high resolution sediment records. Here we present new surface water records from sediment core MD07-3128 recovered at 53°S off the Pacific entrance of the Strait of Magellan. The alkenone-derived sea surface temperature (SST) record reveals a very strong warming of ca. 8°C over the last Termination and substantial millennial-scale variability in the glacial section largely consistent with our planktonic foraminifera oxygen isotope (d18O) record of Neogloboquadrina pachyderma (sin.). The timing and structure of the Termination and some of the millennial-scale SST fluctuations are very similar to those observed in the well-dated SST record from ODP Site 1233 (41°S) and the temperature record from Drowning Maud Land Antarctic ice core supporting the hemispheric-wide Antarctic timing of SST changes. However, differences in our new SST record are also found including a long-term warming trend over Marine Isotope Stage (MIS) 3 followed by a cooling toward the Last Glacial Maximum (LGM). We suggest that these differences reflect regional cooling related to the proximal location of the southern Patagonian Ice Sheet and related meltwater supply at least during the LGM consistent with the fact that no longer SST cooling trend is observed in ODP Site 1233 or any SST Chilean record. This proximal ice sheet location is documented by generally higher contents of ice rafted debris (IRD) and tetra-unsaturated alkenones, and a slight trend toward lighter planktonic d18O during late MIS 3 and MIS 2.

Origen temporal y creación del mundo : la doble vía argumentativa de Tomás de Aquino

En medio de las disputas del siglo XIII, Tomás de Aquino afirma en el Commentarium in Sententiis, primera composición filosófico- teológica, que “a la creación no sólo se la alcanza a través de la fe, sino por la demostración racional". Esta idea no la abandona en ningún momento y la mantiene a lo largo de su obra. Constituye nuestro propósito en el presente trabajo establecer la relación existente entre la estrategia argumentativa que el autor desarrolla en torno a dos problemas: el de la creación y el del origen temporal del mundo, señalando las dos vías argumentativas utilizadas, una que concluye demostrativamente y la otra que expresa la imposibilidad de justificar racionalmente el tema. La clave argumentativa que según entendemos le permite diferenciar el doble orden de explicación radica en la distinción entre causas por sí y por accidente: una causa A está esencialmente ordenada a una causa B, si la acción de B es necesaria para que la acción de A haya tenido lugar. De modo que para alcanzar el efecto, es necesario admitir una causa primera, y entre los dos términos la distancia o el número de causas esencialmente ordenadas a la causa primera debe ser necesariamente finito. Distinto es el caso si se considera el orden de la temporalidad inscripto en el marco de la causalidad accidental: un mundo eterno o no, es algo que no se puede justificar racionalmente en cuanto es un efecto accidental que procede de una causa que obra con absoluta libertad. Entendemos que esta distinción es el instrumento conceptual que le permite a Aquino delimitar epistémicamente entre lo que es posible justificar con certeza, tal es el caso de las argumentaciones que ofrece en torno a la creación; lo que sólo lo es de modo probable, en particular las argumentaciones con base en las doctrinas físicas aristotélicas; y finalmente, aquello que el hombre únicamente puede llegar a conocer a través de la Revelación, como es el caso del conocimiento de un inicio temporal del mundo.

Animations of micro-computed tomography of a pleistocene terebratulid brachiopod

The dorsal valve of a Pleistocene terebratulid brachiopod, Terebratula scillae Seguenza, 1871, has developed a malignant cyst due to colonization in vivo by an endolithic sponge.This trace fossil is a compound boring and bioclaustration structure, representing a boring that has grown in unison with the growth of the cyst. The brachiopod has grown to adult size and growthlines indicate that it was colonised by the sponge when about half grown. Malformation of the shell may not have caused the death of the brachiopod and the sponge does not appear to have outlived its host; both symbionts seem to have died more or less simultaneously. This minus-minus relationship of two symbionts is considered to be a case of 'accidental symbiosis'.

Una triangulación estratégica : Estudio ambiental de una bioinvasión acuática

La educación ambiental es una disciplina formada por componentes naturales y socioculturales del ambiente. Los estudiantes del Profesorado, desarrollan su comprensión conceptual y aprenden más acerca de la naturaleza de la ciencia participando en investigaciones científicas, generando conocimientos que ellos mismos impartirán a sus futuros alumnos. Además, se apropian del método científico a través de la práctica del mismo y no simplemente de la teoría, que suele crear conceptualmente una barrera entre la acción y los resultados alcanzados. Por su parte, las bioinvasiones constituyen una de las amenazas de mayor crecimiento y más significativas para la conservación de la biodiversidad global. La inconciencia del hombre determina el traslado voluntario o accidental de especies desde su hábitat nativo hacia sitios que no habrían podido alcanzar en forma natural. El desafío reside, entonces, en que hay que prevenir las bioinvasiones y, es en este sentido, un rol determinante el de la educación a la sociedad. En el año 2005, se detecta, en Monte Caseros, Corrientes, el comienzo de una bioinvasión (el mejillón dorado, causante de "macrofouling"). A partir de esta invasión, a través de un Acuerdo entre UNLP, IFD de Monte Caseros y la ONG Asociación Ecologista Río Mocoretá, se desarrolla un trabajo que tiene como propósito que los alumnos logren una construcción significativa del conocimiento, afianzando la interacción entre ciencia, educación y sociedad, a fin de lograr la acción directa de la enseñanza, generando conciencia ante este reciente y preocupante problema económico-ambiental en la región Neotropical.

La crítica como búsqueda cooperativa de la verdad : El argumento del tercer hombre en el Sobre las Ideas de Aristóteles

La versión más precisa del argumento "del tercer hombre" es la proporcionada por Aristóteles en el tratado Sobre las ideas. En este trabajo ofreceré, en primer lugar, un análisis del argumento, estableciendo sus presupuestos que lo tornan una crítica válida. En segundo lugar, me detendré en la posible respuesta platónica a la objeción con el propósito de mostrar que Aristóteles descubre una dificultad genuina en la posición platónica: la separación entre Ideas y particulares conlleva el problema de la homonimia. Creemos que una reflexión profunda en torno al argumento condujo a Aristóteles a establecer la importante distinción entre predicación esencial y predicación accidental así como a sostener que existe una relación de sinonimia entre el sujeto y su esencia. En tal sentido, el examen de este argumento ilustra el modo en que para Aristóteles la crítica es un procedimiento válido y habitual en la búsqueda cooperativa de la verdad

Francisco Berra y la educación positivista en el Uruguay (1874-1882)

Las ideas de Berra sobre la enseñanza, que tendían a hacer imperar en la educación una rígida metodología naturalista, ejercieron su influencia sobre la educación argentina, aún antes de su actuación en el gobierno escolar de la provincia de Buenos Aires. A través de su archivo documental puede conocerse la vida intelectual rioplatense -en ambas orillas-, así como el mundo estrictamente escolar y sus manifestaciones pedagógicas correspondientes. En este trabajo, nos proponemos estudiar su actuación en el Uruguay entre los años 1874 a 1882, cuya elección no es casual. Este período comprende el inicio de su actividad pedagógica en Uruguay, la elaboración de su obra principal ("Los apuntes de pedagogía") y su participación en el Congreso pedagógico de Buenos Aires, en pleno embate entre liberales y clericales y las polémicas desatadas por el avance del positivismo.

Late Pliocene carbonate mineralogy of ODP Hole 133-818B

Shedding of shallow carbonate material toward the deep slopes and basin floors is clearly tied to the position of the carbonate bank tops relative to the photic zone. The onset of bank shedding in periplatform sediments can record either the flooding of the bank tops within the photic zone during a rise in sea level following a period of exposure, referred to in the literature as the "highstand shedding" scenario, or the reentry of the bank tops into the photic zone during a lowering of sea level following a period of drowning, referred to as the "lowstand shedding" scenario. Results from Leg 133 post-cruise research on the Pliocene sequences, drilled in six sites within different slope settings of the Queensland Plateau, seem to point out that the latter "lowstand shedding" scenario can be applied to this particular carbonate system. At the Queensland Plateau sites, the early Pliocene (5.2-3.5 Ma) and the earliest part of the late Pliocene (3.5-2.9 Ma) age sequences were characterized, especially in the ôdeepö Sites 811 and 817, by pelagic sediments (foraminifers and coccoliths) and by typically pelagic sedimentation rates not exceeding 20 mm/k.y. The earliest part of the late Pliocene age section was characterized by well-developed hardgrounds in the "shallow" Sites 812 and 814 and by normal pelagic sediments mixed with reworked phosphatized planktonic foraminifers in Site 813. Finally, the early part of the late Pliocene (2.9-2.4 Ma) section was characterized by high sedimentation rates, related to the shedding and admixture into the pelagic sediments of bank-derived materials. These bank-derived materials consist of either diagenetically unaltered fine aragonite with traces of dolomite in Site 818 or micritic calcite resulting from seafloor and/or shallow burial alteration in the deepest Sites 817 and 811. The highest sedimentation rates (163 mm/k.y.) were recorded in Site 818, drilled nearest the modern carbonate bank of Tregrosse Reef. The sedimentation rates decrease with increasing distance from Tregrosse Reef - 120 mm/k.y. in Site 817 and 47.5 mm/k.y. in Site 811. The initial appearance of fine aragonite in Site 818, corresponding to the transition from pelagic to periplatform sedimentation rates, has been dated at 2.9 Ma. This Pliocene sediment pattern on the Queensland Plateau is different from the pattern observed in sediments from two earlier ODP legs (i.e., Leg 101 in the Bahamas and in Leg 115 in the Maldives), where aragonite-rich sediments, characterized by high periplatform sedimentation rates, were observed in the lower Pliocene section (5.2-3.5 Ma), whereas the upper Pliocene (3.5-1.6 Ma) sediments are more pelagic in nature and are characterized by low sedimentation rates or major hiatuses. These Pliocene periplatform sequences in the Bahamas and in the Maldives and late Quaternary age periplatform sequences worldwide have pointed out that "highstand shedding" was the typical response of carbonate platforms to fluctuations in sea level, just opposite to a "lowstand shedding" response to sea-level fluctuations, typical of siliciclastic shelves. Assuming that the envelope of Haq et al.'s (1987) sea-level curve, showing a well-defined lowering of sea level between 3.5 and 2.9 Ma, can also be applied to the southwest Pacific Ocean, based on a high-resolution Pliocene d18O record from the Ontong Java Plateau recently published by Jansen et al. (1993, doi:10.2973/odp.proc.sr.130.028.1993), the Pliocene periplatform sequences on the Queensland Plateau would have recorded the reentry of the bank tops into the photic zone during a general lowering of sea level, following an interval characterized by high sea level, during which the shallow carbonate system on the Queensland Plateau was drowned. The early Pliocene age (5.2-3.5 Ma) sediments deposited on the Queensland Plateau, an established interval of eustatic sea-level highstand, are typically pelagic in character. In addition, relatively cold surface temperatures (estimated to have ranged from 18° to 20°C by Isern et al. [this volume]) might have also stressed the reefs during early Pliocene time and contributed to the drowning of the Queensland Plateau carbonate system during the late Miocene and early Pliocene. Differential and relatively high subsidence rates, inferred by variations in paleodepth of water (based upon benthic foraminifer assemblages; Katz and Miller, this volume) may also have influenced the drowning of the carbonate bank tops on the Queensland Plateau during the late Miocene and early Pliocene. The sediments of early late Pliocene age (2.9-2.4 Ma), a well-established interval of lowering of sea level, are clearly periplatform and cyclic in nature. High-frequency (~40 k.y.) aragonite cycles, well-developed between 2.9 and 2.45 Ma, correlate with the planktonic high-resolution Pliocene d18O record from the Ontong Java Plateau, a good sea-level proxy (Jansen et al., in press). Contrary to late Quaternary age aragonite cycles from the Bahamas, the Nicaragua Rise, the Maldives, and the Queensland Plateau, the late Pliocene aragonite cycles in Hole 818B display high levels of aragonite during glacial stages and, therefore, lowstands of sea level. In addition, sediments deposited during the earliest part of the late Pliocene (3.5-2.9 Ma), transition between the early Pliocene highstand and the late Pliocene lowering in sea level, have recorded the first evidence of a fall in sea level, by (1) the occurrence of synchronous submarine hardgrounds in the two shallowest sites (Sites 812 and 814), (2) the deposition of reworked material from the shallower part of the slope into the intermediate Sites 813 and 818, and (3) the deposition of pelagic sediments in the deepest Sites 817 and 817. In summary, contrary to previous findings, the Pliocene periplatform sediments on the Queensland Plateau appear to have recorded a regional shedding of shallow carbonate bank tops during an interval of sea-level lowering, a good illustration of the "carbonate lowstand shedding" scenario, occurring during the reentry of previously drowned carbonate bank tops into the photic zone related to a decrease in sea level.