Effects observed in the Latin American sector ionospheric F region during the intense geomagnetic disturbances in the early part of November 2004

The Sun was very active in the early part of November 2004. During the period of 8-10 November 2004, intense geomagnetic disturbances with two superstorms were observed. In this paper, we have investigated the generation and suppression of equatorial ionospheric irregularities and the daytime changes in the F region electron density in the Latin American sector during the period of intense geomagnetic disturbances. We present the ionospheric sounding observations carried out at Manaus and Sao Jose dos Campos, Brazil, during this geomagnetically disturbed period. Also, GPS observations obtained from several stations in Brazil, Argentina, and St. Croix, U.S. Virgin Islands, during the disturbed period are presented. During the main phase of the first superstorm, around the prereversal enhancement time (night of 7-8 November), prompt penetration of electric field was observed and the presence of equatorial ionospheric irregularities was detected from St. Croix, U.S. Virgin Islands (in the northern hemisphere) to Bahia Blanca, Argentina (in the southern hemisphere). The ionospheric sounding observations at Manaus indicate inhibition of prereversal enhancement on the nights of 9-10 and 10-11 November, possibly due to the disturbed thermospheric winds or disturbance electric fields. Virtually no phase fluctuations on the nights of 9-10 and 10-11 November were observed in the Latin American sector. During the daytime on 8 November, the vertical total electron content (VTEC) observations show a negative storm phase at Porto Alegre (Brazil) and Bahia Blanca (Argentina). Again during the daytime on 10 November, the VTEC observations show a negative storm phase from Brasilia (Brazil) to Bahia Blanca. These negative storm phases are associated with a decrease in the O/N2 ratio. During the daytime on 9 November, the VTEC observations show a positive storm phase extending from St. Croix to Porto Alegre, and again on 10 November, VTEC observations show a positive storm phase. These positive storm phases observed are possibly due to changes in large-scale wind circulation and an increase in the O/N2 ratio.Facultad de Ciencias Astronómicas y Geofísica

Avanços metodológicos na determinação do consumo de ruminantes em pastejo Advances in methods for determining animal intake on pasture

Avanços metodológicos são, usualmente, conseqüência direta de avanços conceituais e tecnológicos. No caso da estimativa do consumo em pastejo, os recentes avanços conceituais relativos ao processo de busca e apreensão da forragem pelo ruminante evidenciaram a importância da unidade básica do consumo o bocado -, e dos fatores limitantes ao consumo que ocorrem antes da ingestão da forragem pelo animal em pastejo. A abordagem reducionista do processo de pastejo, aliada à sua hierarquização espaço-temporal, trouxeram uma nova concepção de como o animal obtém o seu alimento do pasto. Destes modelos conceituais emergiram novas variáveis que requerem novos procedimentos experimentais e analíticos. Neste contexto, importantes avanços têm ocorrido. Este artigo apresenta e discute os novos procedimentos que permitem estimar o consumo no curto prazo, assim como aqueles mais utilizados pela comunidade científica nacional para estimar o consumo no longo prazo. Adicionalmente, são feitas também considerações sobre o uso de animais ou de piquetes como unidades experimentais em experimentos de pastejo. Conclui-se que, apesar de ainda existir importantes barreiras metodológicas, os recentes avanços conceituais sobre o processo de pastejo, assim como dos procedimentos analíticos, geram fortes expectativas de avanço em curto e médio prazo na obtenção de estimativas qualificadas de consumo por animais em pastejo.<br>Methodological advances are usually a direct consequence of conceptual and technical advances. In the case of animal intake on pasture, recent conceptual advances regarding the process of searching and apprehension of the forage by the ruminant provide insight regarding the importance of the basic unit of intake, the bite, and the importance of processes limiting intake that occur before the forage reaches the rumen. Applying a reductionist approach to the grazing process, along with its spatial-temporal hierarchy, brought a new conceptualization of how an animal obtains feed from pasture. From the conceptual models emerged new variables that required new experimental and analytical procedures. Within this context, important advances have occurred. This article describes the new procedures that allow to estimate the consumption on the short-term, as well as that most utilized by the national scientific community for estimating the consumption on the long-term. Procedure for estimating fecal production and digestibility are discussed, as well as the use of n-alkanes and other emerging techniques. Consideration is given to the use of animals or paddocks as experimental units in grazing experiments. The conclusions presented in this article do not differ from those of preceding articles regarding this subject. In a grazing condition, continuous intake is the "black box" to be revealed, complex by nature with regard to the animal as well as the pasture, and there are important methodological barriers toward is determination. Nevertheless, recent advances in conceptualizing the grazind process, as well as in the analytical procedures, have been considerable and generate ambitious expectations over the short and long term

Safety and efficacy of non-steroidal anti-inflammatory drugs to reduce ileus after colorectal surgery

Background: Ileus is common after elective colorectal surgery, and is associated with increased adverse events and prolonged hospital stay. The aim was to assess the role of non-steroidal anti-inflammatory drugs (NSAIDs) for reducing ileus after surgery. Methods: A prospective multicentre cohort study was delivered by an international, student- and trainee-led collaborative group. Adult patients undergoing elective colorectal resection between January and April 2018 were included. The primary outcome was time to gastrointestinal recovery, measured using a composite measure of bowel function and tolerance to oral intake. The impact of NSAIDs was explored using Cox regression analyses, including the results of a centre-specific survey of compliance to enhanced recovery principles. Secondary safety outcomes included anastomotic leak rate and acute kidney injury. Results: A total of 4164 patients were included, with a median age of 68 (i.q.r. 57\u201375) years (54\ub79 per cent men). Some 1153 (27\ub77 per cent) received NSAIDs on postoperative days 1\u20133, of whom 1061 (92\ub70 per cent) received non-selective cyclo-oxygenase inhibitors. After adjustment for baseline differences, the mean time to gastrointestinal recovery did not differ significantly between patients who received NSAIDs and those who did not (4\ub76 versus 4\ub78 days; hazard ratio 1\ub704, 95 per cent c.i. 0\ub796 to 1\ub712; P = 0\ub7360). There were no significant differences in anastomotic leak rate (5\ub74 versus 4\ub76 per cent; P = 0\ub7349) or acute kidney injury (14\ub73 versus 13\ub78 per cent; P = 0\ub7666) between the groups. Significantly fewer patients receiving NSAIDs required strong opioid analgesia (35\ub73 versus 56\ub77 per cent; P &lt; 0\ub7001). Conclusion: NSAIDs did not reduce the time for gastrointestinal recovery after colorectal surgery, but they were safe and associated with reduced postoperative opioid requirement