Seasonal Divergence of Landscape Use by Heritage and Conventional Cattle on Desert Rangeland

Adopting livestock with heritage genetics may help to improve the sustainability of agriculture on rangelands with harsh, challenging conditions. In the Chihuahuan Desert, preliminary evidence suggests that heritage Raramuri Criollo exploit a greater variety of range resources than do conventional cattle. Accordingly, the use of Raramuri Criollo may help sustain vegetation and soils, as well as agricultural production. To explore these possibilities, we used Global Positioning System collars to track Angus × Hereford and Raramuri Criollo cows in a 1 535-ha pasture in southern New Mexico in June–December 2008. As predicted on the basis of past research, home range sizes of Raramuri Criollo exceeded those of Angus × Hereford during seasons with low forage availability—by 31.4 ± 6.5 ha during Pregreenup and 17.2 ± 6.5 ha during Drydown—but sizes converged during more productive seasons (Greenup 1, Greenup 2). Angus × Hereford allotted more daily time to resting, with the difference most pronounced during Drydown (71.1 ± 21.1 min day^{? 1}). Angus × Hereford had twice as many hotspots of use (locations with multiple visits of long duration), with seasonal timing and location corresponding with distribution patterns known to impact desirable natural resources. Raramuri Criollo more strongly preferred the Bare/Forbs ecological state with seasonal timing that possibly signals an ability to use nutritious forbs on open ground despite summer heat. Results are consistent with conjectures that compared with conventional cattle, Raramuri Criollo have greater daily mobility and wider spatial distribution during dry seasons. Although not directly measured, results also suggest that the heritage breed has superior heat tolerance and lower impact on desirable natural resources. These findings provide evidence that Raramuri Criollo can support sustainable livestock production in the Chihuahuan Desert, but direct measurements of profitability and environmental effects are needed before adoption can be recommended widely.     

Evaluation of different concentrations of adult live Artemia (Artemia franciscana,Kellogs 1906) as natural exogenous feed on the water quality and production parameters of Litopenaeus vannamei (Boone 1931) pre-grown intensively

A 7-week experimental study was performed to evaluate the effect of five concentrations of adult live Artemia (0, 1, 2, 3 and 4 L⁻¹) as exogenous natural feed on the water quality and production parameters of juvenile (0.2 ± 0.01 g) shrimp (Litopenaeus vannamei) pre-grown intensively (125 organism m⁻²) under laboratory conditions (80 L plastic tanks). No significant differences were observed in the environmental variables among treatments. Total ammonium nitrogen, nitrates and phosphates recorded higher concentrations in all the treatments using artemia, as compared with the treatment without Artemia. In all the cases, the levels remained within or close to the ranges considered necessary for the farming of the species. The highest weight gain and biomass were obtained in the treatments with 3 and 4 Artemia L⁻¹. The best feed conversion ratio were recorded using 2 Artemia L⁻¹ and the highest with 0 Artemia L⁻¹. No differences in survival were detected among treatments. The greatest concentrations of nitrogenous metabolites achieved at the highest densities of Artemia were lower than the LC₅₀ for penaied shrimp and no negative effect was observed on the survival of the shrimp. These results clearly indicate that the use of adult live Artemia as exogenous natural feed significantly increased the production parameters of the Pacific white shrimp.     

Long-term in situ Toxicity Bioassays of the Reconquista River (Argentina) Water with Cyprinus carpio as Sentinel Organism

Since the early 1970s, more than 25% of Japanese red pine forests have died or declined in Hiroshima Prefecture, Japan. Mass mortality phenomenon of pine trees has appeared throughout Japan, expanding northward from the Prefectures in southern Japan such as Nagasaki, Kogashima. The mortality was above 80% in Nagasaki, Kumamoto, Miyazaki and Tokyo. This study shows that the massive mortality of pines forest mainly occurred in south-facing slopes, where mortality was 90% in Gokurakujisann Mount, Hiroshima. The mortality was very low, < 3.7%, on north-facing slopes and mountain peaks. On west-facing slopes, the mortality was 20–40%. The foliar phenological development on south-facing slopes was 14 days earlier than that on north-facing slopes, 18 days earlier than that on mountain peaks. The mortality of pine trees in Gokurakujisann Mount increased with earlier phenological development and was significantly correlated (R = 0.98^**). The mortality of pine trees in each Prefecture increased from south to north with earlier phenological progress and was significantly correlated (R = 0.56^**). The outbreak of pine tree mortality was closely related to appearance of abnormally extreme lowest air temperature in February and March. The annual ring width in Gokurakujisann Mount was decreased from 1972 to 1984, concomitantly the abnormally extreme lowest air temperature in February and March. Based on these, it may be concluded that the combined effects of accelerated phenological progress and reduced frost hardiness caused by acid deposition, mainly nitrogen deposition, and extreme abnormally lowest air temperature in late winter and early spring in February and March are the original main factors of mortality of pine trees on a large scale.     

Influence of Cadmium on the Respiratory Function of the Grass Carp Ctenopharyngodon idella

The effect of 96 h exposure tosublethal cadmium concentrations on oxygen consumptionrate (VO₂ mg h^-1) and oxygen extractionefficiency (OEE′ %) was determined in juvenile Ctenopharyngodon idella acclimated to 26, 29 and 32 °C for at least two weeks. The relationshipsamong the physiological rates (VO₂ andOEE′, body weight and temperature, were fittedby second order polynomial models; the responsesurfaces generated allowed the evaluation of stressinduced by the interaction of those variables. BothVO₂ and OEE′ invariably increased astemperature increased. In small animals kept in 0.5 mgCd L^-1, the VO₂ increase was compensated bya proportional increase in OEE′, whereas inlarger fishes (>1 g) no compensatory response wasobserved. Both small and large fishes were unable tocompensate for a higher VO₂ when exposed tohigher cadmium concentration. It is concluded thatOEE′ in young fish is an early response of stressdue to sublethal cadmium exposure.     

Sequence finishing and mapping of Drosophila melanogaster heterochromatin

Genome sequences for most metazoans and plants are incomplete because of the presence of repeated DNA in the heterochromatin. The heterochromatic regions of Drosophila melanogaster contain 20 million bases (Mb) of sequence amenable to mapping, sequence assembly, and finishing. We describe the generation of 15 Mb of finished or improved heterochromatic sequence with the use of available clone resources and assembly methods. We also constructed a bacterial artificial chromosome-based physical map that spans 13 Mb of the pericentromeric heterochromatin and a cytogenetic map that positions 11 Mb in specific chromosomal locations. We have approached a complete assembly and mapping of the nonsatellite component of Drosophila heterochromatin. The strategy we describe is also applicable to generating substantially more information about heterochromatin in other species, including humans.     

Determination of Water Fluoride Concentration and the Influence of the Geographic Coordinate System and Time

The upper limit of fluoride concentration in water for human consumption is 1.5?ppm. Many studies have been carried out concerning the water fluoride concentration in wide areas around the world, but none have studied the change of fluoride concentration as a function of geographical coordinates and through time. This paper describes ??microvariation?? of fluoride concentration among wells separated by less than 500?m in a month. On the other hand, ??macrovariation?? is also studied describing changes among cities that are separated by more than 10?km and compared with fluoride concentrations measured 65?years ago. Fluoride concentration was measured in a wide geographical area of Argentina, which is 133,000?km². Samples of water were collected from different regions. Macrovariation: Differences in fluoride concentration in well water among regions were found, as well as an increase in water fluoride concentration during seven decades. Microvariation: Daily water fluoride concentration in a specific area displayed a great variation in the measurements through time. In addition, wells with no more than 500?m of separation were measured at the same time and were significantly different. These results indicate that in order to determine the fluoride concentration of a region, different samples of the same area should be obtained and a sampling through time should also be done.     

Oldest writing in the New World

A block with a hitherto unknown system of writing has been found in the Olmec heartland of Veracruz, Mexico. Stylistic and other dating of the block places it in the early first millennium before the common era, the oldest writing in the New World, with features that firmly assign this pivotal development to the Olmec civilization of Mesoamerica.     

Selenium species in aqueous extracts of alfalfa sprouts by two-dimensional liquid chromatography coupled to inductively coupled plasma mass spectrometry and electrospray mass spectrometry detection

The complementary use of two different liquid chromatographic mechanisms coupled to inductively coupled plasma mass spectrometry (ICP-MS) for selenium (Se) specific detection has permitted the screening of the most abundant Se-containing fractions in selenized alfalfa sprouts (Medicago sativa). Aqueous extracts of the sprouts were fractionated first by size exclusion chromatography (SEC) using a Superdex Peptide column and a mobile phase containing an ammonium acetate buffer (pH 7). Further purification of the individual SEC Se-containing fractions was carried out using two different chromatographic systems: a Shodex Ashaipack column, with a mixed mechanism of size exclusion and ion exchange, and a conventional reversed phase C8 using ion-pairing reagents. In both cases, the columns were coupled to an inductively coupled plasma mass spectrometer equipped with an octapole reaction system for Se specific detection. This system allowed the on-line monitoring of the most abundant Se isotopes (78Se, 80Se) by reducing the possible polytomic interferences affecting these ions by adding hydrogen (2 mL min(-1)) to the octapole reaction cell. The results obtained by both separation mechanisms were highly comparable, revealing the presence of Se-methionine and Se-methyl selenocysteine. Both compounds were then confirmed by analyzing the corresponding fractions by electrospray quadrupole-time-of-flight (ESI-Q-TOF) mass spectrometry. Finally, an additional Se-containing species showing Se isotope distribution was detected at a molecular ion m/z 239 in the ESI-Q-TOF. The collision-induced dissociation of the m/z 239 and 237 ions (corresponding to 80Se and 78Se isotopes, respectively) revealed the possible presence as well of a derivative of the Se-2-propenyl selenocysteine.     

Greenhouse evaluation of struvite and sludges from municipal wastewater treatment works as phosphorus sources for plants

Sewage sludge obtained by a conventional aerobic activated sludge process (CSS), P-rich sewage sludge from an enhanced biological P removal process (PRS), and struvite (MgNH 4PO 4 x 6H 2O) recovered from an anaerobic digester supernatant using a low-grade MgO byproduct from the calcination of natural magnesite as a Mg source (STR) were evaluated as P sources for plant growth. For this purpose, a greenhouse pot experiment was conducted using a P-deficient loamy sand soil and perennial ryegrass ( Lolium perenne L.) as the test crop. The P sources were applied at rates equivalent to 0, 9, 17, 26, 34, and 44 mg/kg P. Single superphosphate (SUP) was used as reference for comparison with the other P sources. The results obtained indicated that STR was as effective as SUP in increasing the dry matter yield and supplying P to ryegrass. Compared to SUP and STR, PRS and especially CSS exhibited less agronomic effectiveness as P sources, which may be attributed, at least partially, to greater soil P fixation because of the larger amount of Fe incorporated with these materials.