Estrategias socio-productivas y agricultura familiar : Las nuevas tecnologías y sus implicancias en las relaciones familiares y productivas en una localidad del sur santafesino

El presente artículo pretende aportar algunos conocimientos teóricos y empíricos sobre las profundas transformaciones del sector rural pampeano argentino, donde los cambios tecnológicos han impactado significativamente en la vida cotidiana y productiva como nunca antes en la historia. En particular, se intenta identificar en qué medida la incorporación de nuevas tecnologías y lógicas productivas modificó el tradicional modelo socio-productivo de tipo familiar que primaba entre los pequeños y medianos productores agropecuarios de una localidad del sur de la provincia de Santa Fe (Bigand), donde desde hace varias décadas viene imponiéndose un proceso sostenido de "agriculturización", tecnificación y especialización de su producción primaria agropecuaria en función del monocultivo de soja. Este trabajo argumenta su diseño metodológico en un estudio de casos e intenta transmitir al lector la complejidad y diversidad de estrategias socio-productivas de los casos de explotaciones agropecuarias seleccionadas en su contexto. Las estrategias de los productores agropecuarios, que derivan de la combinación compleja de factores económicos y sociales en cada caso, nos permitieron observar el grado de articulación entre emprendimiento productivo y proyecto familiar, y la incidencia del "factor tecnológico" y del contexto socio-productivo de esta localidad del sur santafesino en cada uno de los mismos

El teatro y el Príncipe : La representación del rey en la Henriada de W. Shakespeare

El teatro es el espacio público más significativo en lo que respecta a la construcción de representaciones en la sociedad de la modernidad. En este sentido, indagaremos sobre las representaciones del poder, particularmente sobre la legitimidad monárquica en el teatro isabelino. Nos centraremos en las obras denominadas Henriada de W. Shakespeare, un autor que se ha detenido particularmente en la figura del rey, del príncipe y de las relaciones de alta política. Indagación que tiene como fin introducirse en la problemática de la legitimidad monárquica a la luz de los sucesos ocurridos en una Europa donde la discusión sobre el poder tendrá importantes consecuencias en los desarrollos posteriores del Estado moderno

Estrategias socio-productivas y agricultura familiar : Las nuevas tecnologías y sus implicancias en las relaciones familiares y productivas en una localidad del sur santafesino

El presente artículo pretende aportar algunos conocimientos teóricos y empíricos sobre las profundas transformaciones del sector rural pampeano argentino, donde los cambios tecnológicos han impactado significativamente en la vida cotidiana y productiva como nunca antes en la historia. En particular, se intenta identificar en qué medida la incorporación de nuevas tecnologías y lógicas productivas modificó el tradicional modelo socio-productivo de tipo familiar que primaba entre los pequeños y medianos productores agropecuarios de una localidad del sur de la provincia de Santa Fe (Bigand), donde desde hace varias décadas viene imponiéndose un proceso sostenido de "agriculturización", tecnificación y especialización de su producción primaria agropecuaria en función del monocultivo de soja. Este trabajo argumenta su diseño metodológico en un estudio de casos e intenta transmitir al lector la complejidad y diversidad de estrategias socio-productivas de los casos de explotaciones agropecuarias seleccionadas en su contexto. Las estrategias de los productores agropecuarios, que derivan de la combinación compleja de factores económicos y sociales en cada caso, nos permitieron observar el grado de articulación entre emprendimiento productivo y proyecto familiar, y la incidencia del "factor tecnológico" y del contexto socio-productivo de esta localidad del sur santafesino en cada uno de los mismos

El teatro y el Príncipe : La representación del rey en la Henriada de W. Shakespeare

El teatro es el espacio público más significativo en lo que respecta a la construcción de representaciones en la sociedad de la modernidad. En este sentido, indagaremos sobre las representaciones del poder, particularmente sobre la legitimidad monárquica en el teatro isabelino. Nos centraremos en las obras denominadas Henriada de W. Shakespeare, un autor que se ha detenido particularmente en la figura del rey, del príncipe y de las relaciones de alta política. Indagación que tiene como fin introducirse en la problemática de la legitimidad monárquica a la luz de los sucesos ocurridos en una Europa donde la discusión sobre el poder tendrá importantes consecuencias en los desarrollos posteriores del Estado moderno

Iridium and other element concentrations and magnetostratigraphy across the Cretaceous/Tertiarty boundary in ODP Hole 122-761C

Samples from Ocean Drilling Program Hole 761C, collected on both sides of the Cretaceous/Tertiary boundary have been analyzed for their chemical and mineralogical content. The sediment consists of nannofossil ooze with variable amounts of clay. The boundary is marked by a color change associated with a nearly step-like decrease of the carbonate fraction. Paleomagnetic data and the drop of the carbonate content indicate that a strong reduction of the sedimentation rate occurred at the boundary and persisted for million of years. An iridium anomaly of 80 ng/cm**2, together with overabundances of Cr and Fe, are found in close coincidence with the planktonic crisis. These enrichments can be explained by the infall of =0.16 g/cm2 of Cl-like chondritic material. Co and Ni enrichments and a great quantity of Ni-rich magnetites are also observed in the basal Danian. These elements and minerals excepted, the composition of the insoluble fraction appears to be nearly unchanged across the boundary. Chemical and mineralogical observations support a cosmic origin for the Cretaceous/Tertiary event but do not reveal the presence of any significant impact ejecta.

Pore-water chemistry of ODP Sites 124-767 and 124-768

The combination of multiple sediment sources and varying rates of sediment accumulation in the Celebes and Sulu seas have had significant impact on the processes of diagenesis, mineralization, and pore-fluid flow. Isotopic and mass-balance calculations help elucidate the various reactions taking place in these western Pacific basins, where ash alteration and basalt-seawater interactions are superimposed on the effects of sulfate oxidation of organic carbon and biogenic methane and of dolomitization of biogenic carbonates. Based on the shape of the calcium and magnesium depth profiles, two major reactive zones have been identified. The first is located near the zone of sulfate depletion and is characterized by carbonate recrystallization, dolomitization and ash alteration reactions at both Ocean Drilling Program Sites 767 and 768. The second reactive zone corresponds to the bottom of the sedimentary sequence and is characterized by alteration reactions in the basement (Site 767) and in the pyroclastic deposits beneath the sediment column (Site 768).

Stable oxygen isotope. Mg/Ca and Temperature record of Caribbean and Pacific sediments

The final phase of the closure of the Panamanian Gateway and the intensification of Northern Hemisphere Glaciation (NHG) both occurred during the Late Pliocene. Glacial-interglacial (G-IG) variations in sea level might, therefore, have had a significant impact on the remaining connections between the East Pacific and the Caribbean. Here, we present combined foraminiferal Mg/Ca and d18O measurements from Ocean Drilling Program (ODP) Site 1241 from the East Pacific and ODP Site 999 from the Caribbean. The studied time interval covers the first three major G-IG Marine Isotope Stages (MIS 95-100, ~2.5 Ma) after the intensification of NHG. Analyses were performed on the planktonic foraminifera Neogloboquadrina dutertrei and Globigerinoides sacculifer, representing water mass properties in the thermocline and the mixed-layer, respectively. Changes in sea water temperature, relative salinity, and water column stratification strongly suggest that the Panamanian Gateway temporarily closed during glacial MIS 98 and 100, as a result of changes in ice volume equivalent to a drop in sea level of 60-90 m. Reconstructed sea surface temperatures (SST) from G. sacculifer show a glacial decrease of 2.5°C at Site 1241, but increases of up to 3°C at Site 999 during glacial MIS 98 and 100 suggesting that the Panamanian Gateway closed during these glacial periods. The Mg/Ca-temperatures of N. dutertrei remain relatively stable in the East Pacific, but do show a 3°C warming in the Caribbean at the onset of these glacial periods suggesting that the closing of the gateway also changed the water column stratification. We infer that the glacial closure of the gateway allowed the Western Atlantic Warm Pool to extend into the southern Caribbean, increasing SST (G. sacculifer) and deepening the thermocline (N. dutertrei). Additionally, ice volume appears to have become large enough during MIS 100 to survive the relatively short lasting interglacial MIS 99 so that the gateway remained closed. Towards the end of MIS 98, during MIS 97 and into MIS 96 temperatures on both sides are mostly similar suggesting water masses exchanged again. Additionally, Caribbean variations in SST and d18Owater follow a precession-like cyclicity rather than the obliquity-controlled variations characteristic of the East-Pacific and many other tropical areas, suggesting that regional atmospheric processes related to the trade winds and the Intertropical Convergence Zone (ITCZ) had a dominant impact in the Caribbean.

Atmospheric nitrate concentrations and isotope composition for samples collected in the marine boundary layer in 2006 and 2007

The comprehensive isotopic composition of atmospheric nitrate (i.e., the simultaneous measurement of all its stable isotope ratios: 15N/14N, 17O/16O and 18O/16O) has been determined for aerosol samples collected in the marine boundary layer (MBL) over the Atlantic Ocean from 65°S (Weddell Sea) to 79°N (Svalbard), along a ship-borne latitudinal transect. In nonpolar areas, the d15N of nitrate mostly deriving from anthropogenically emitted NOx is found to be significantly different (from 0 to 6 per mil) from nitrate sampled in locations influenced by natural NOx sources (-4 ± 2) per mil. The effects on d15N(NO3-) of different NOx sources and nitrate removal processes associated with its atmospheric transport are discussed. Measurements of the oxygen isotope anomaly (D17O = d17O - 0.52 × d18O) of nitrate suggest that nocturnal processes involving the nitrate radical play a major role in terms of NOx sinks. Different D17O between aerosol size fractions indicate different proportions between nitrate formation pathways as a function of the size and composition of the particles. Extremely low d15N values (down to -40 per mil) are found in air masses exposed to snow-covered areas, showing that snowpack emissions of NOx from upwind regions can have a significant impact on the local surface budget of reactive nitrogen, in conjunction with interactions with active halogen chemistry. The implications of the results are discussed in light of the potential use of the stable isotopic composition of nitrate to infer atmospherically relevant information from nitrate preserved in ice cores.

Stable oxygen isotope ratios of marine barite from Cenozoic sediments

We report new data on oxygen isotopes in marine sulfate (delta18O[SO4]), measured in marine barite (BaSO4), over the Cenozoic. The delta18O[SO4] varies by 6x over the Cenozoic, with major peaks 3, 15, 30 and 55 Ma. The delta18O[SO4] does not co-vary with the delta18O[SO4], emphasizing that different processes control the oxygen and sulfur isotopic composition of sulfate. This indicates that temporal changes in the delta18O[SO4] over the Cenozoic must reflect changes in the isotopic fractionation associated with the sulfide reoxidation pathway. This suggests that variations in the aerial extent of different types of organic-rich sediments may have a significant impact on the biogeochemical sulfur cycle and emphasizes that the sulfur cycle is less sensitive to net organic carbon burial than to changes in the conditions of that organic carbon burial. The delta18O[SO4] also does not co-vary with the d18O measured in benthic foraminifera, emphasizing that oxygen isotopes in water and sulfate remain out of equilibrium over the lifetime of sulfate in the ocean. A simple box model was used to explore dynamics of the marine sulfur cycle with respect to both oxygen and sulfur isotopes over the Cenozoic. We interpret variability in the delta18O[SO4] to reflect changes in the aerial distribution of conditions within organic-rich sediments, from periods with more localized, organic-rich sediments, to periods with more diffuse organic carbon burial. While these changes may not impact the net organic carbon burial, they will greatly affect the way that sulfur is processed within organic-rich sediments, impacting the sulfide reoxidation pathway and thus the delta18O[SO4]. Our qualitative interpretation of the record suggests that sulfate concentrations were probably lower earlier in the Cenozoic.

Sponge bioerosion accelerated by ocean acidification across species and latitudes?

In many marine biogeographic realms, bioeroding sponges dominate the internal bioerosion of calcareous substrates such as mollusc beds and coral reef framework. They biochemically dissolve part of the carbonate and liberate so-called sponge chips, a process that is expected to be facilitated and accelerated in a more acidic environment inherent to the present global change. The bioerosion capacity of the demosponge Cliona celata Grant, 1826 in subfossil oyster shells was assessed via alkalinity anomaly technique based on 4 days of experimental exposure to three different levels of carbon dioxide partial pressure (pCO2) at ambient temperature in the cold-temperate waters of Helgoland Island, North Sea. The rate of chemical bioerosion at present-day pCO2 was quantified with 0.08-0.1 kg/m**2/year. Chemical bioerosion was positively correlated with increasing pCO2, with rates more than doubling at carbon dioxide levels predicted for the end of the twenty-first century, clearly confirming that C. celata bioerosion can be expected to be enhanced with progressing ocean acidification (OA). Together with previously published experimental evidence, the present results suggest that OA accelerates sponge bioerosion (1) across latitudes and biogeographic areas, (2) independent of sponge growth form, and (3) for species with or without photosymbionts alike. A general increase in sponge bioerosion with advancing OA can be expected to have a significant impact on global carbonate (re)cycling and may result in widespread negative effects, e.g. on the stability of wild and farmed shellfish populations, as well as calcareous framework builders in tropical and cold-water coral reef ecosystems.

Tough as a rock-boring urchin: adult Echinometra sp. EE from the Red Sea show high resistance to ocean acidification over long-term exposures

Ocean acidification, a process caused by the continuous rise of atmospheric CO2 levels, is expected to have a profound impact on marine invertebrates. Findings of the numerous studies conducted in this field indicate high variability in species responses to future ocean conditions. This study aimed at understanding the effects of long-term exposure to elevated pCO2 conditions on the performance of adult Echinometra sp. EE from the Gulf of Aqaba (Red Sea). During an 11-month incubation under high pCO2 (1,433 µatm, pHNBS 7.7) and control (435 µatm, pHNBS 8.1) conditions, we examined the urchins' somatic and gonadal growth, gametogenesis and skeletal microstructure. Somatic and gonadal growths were exhibited with no significant differences between the treatments. In addition, all urchins in the experiment completed a full reproductive cycle, typical of natural populations, with no detectable impact of increased pCO2 on the timing, duration or progression of the cycle. Furthermore, scanning electron microscopy imaging of urchin tests and spines revealed no signs of the usual observed effects of acidosis, such as skeletal dissolution, widened stereom pores or non-smoothed structures. Our results, which yielded no significant impact of the high pCO2 treatment on any of the examined processes in the urchins studied, suggest high resistance of adult Echinometra sp. EE to near future ocean acidification conditions. With respect to other findings in this area, the outcome of this study provides an example of the complicated and diverse responses of echinoids to the predicted environmental changes.

Economic Reform and Social Sector Expenditures: A Study of Fifteen Indian States 1980/81-1999/2000

This paper examines social sector expenditures in fifteen Indian states between 1980/81 and 1999/2000 to find out whether the far-reaching economic reforms that began in 1991 had any significant impact on the level and trend of these expenditures; and if there was any such impact, what were the reasons behind the ensuing changes. The empirical analysis in this study shows that revenue became a major determinant of social sector expenditures from the mid 1980s with the result that real per capita social sector expenditures in most states started to decline even before the economic reforms began as states' fiscal deficits worsened in the 1980s. Economic reforms, therefore, largely did not have a major negative impact on expenditures. In fact there was a positive impact on some states, which often were those that received more foreign aid than other states. By the late 1990s, states expending more on the social sector changed from states with a traditionally strong commitment to the social sector, such as Kerala, to states having higher revenues including aid from outside the country.

Is Learning by Migrating to a Megalopolis Really Important? Evidence from Thailand

We examine the effects of learning by migrating on the productivity of migrants who move to a "megalopolis" from rural areas using the Thailand Labor Force Survey. The main contribution is to the development a simple framework to test for self-selection on migration decisions and learning by migrating into the urban labor market, focusing on experimental evidence in the observational data. The role of the urban labor market is examined. In conclusion, we find significant evidence for sorting: the self-selection effects test (1) is positive among new entrants from rural areas to the urban labor market; and (2) is negative among new exits that move to rural areas from the urban labor market. Further, estimated effects of learning by migrating into a "megalopolis" have a less significant impact. These results suggest the existence of a natural selection (i.e. survival of the fittest) mechanism in the urban labor market in a developing economy.

Ramadan school holidays as a natural experiment : impacts of seasonality on school dropout in Bangladesh

In 2000, Ramadan school vacation coincided with the original annual exam period of December in Bangladesh. This forced schools to pre-pone their final exam schedules in November, which was the month before the harvest begins. 'Ramadan 2000' is a natural experiment that reduced the labor demand for children during the exam period. Using household level panel data of 2000 and 2003, and after controlling for various unobservable variations including individual fixed effects, aggregate year effects, and subdistrict-level year effects, this paper finds evidence of statistically significant impact of seasonal labor demand on school dropout in Bangladesh among the children from agricultural households.

The Role of Patents in the Advent of Web 2.0

Given the significant impact of Web 2.0-related innovations on new Internet-based initiatives, this paper seeks to identify to what extent the main developments are protected by patents and whether patents have had a leading role in the advent of Web 2.0. The article shows that the number of patent applications filed is not that important for many of the Web 2.0 technologies in frequent use and that, of those filed, those granted are even less. The conclusion is that patents do not seem to be a relevant factor in the development of the Web 2.0 (and more generally in dynamic markets) where there is a high degree of innovation and low entry barriers for newcomers.