RESUMO
Wheat yields globally will depend increasingly on good management to conserve rainfall and new varieties that use water efficiently for grain production. Here we propose an approach for developing new varieties to make better use of deep stored water. We focus on water-limited wheat production in the summer-dominant rainfall regions of India and Australia, but the approach is generally applicable to other environments and root-based constraints. Use of stored deep water is valuable because it is more predictable than variable in-season rainfall and can be measured prior to sowing. Further, this moisture is converted into grain with twice the efficiently of in-season rainfall since it is taken up later in crop growth during the grain-filling period when the roots reach deeper layers. We propose that wheat varieties with a deeper root system, a redistribution of branch root density from the surface to depth, and with greater radial hydraulic conductivity at depth would have higher yields in rainfed systems where crops rely on deep water for grain fill. Developing selection systems for mature root system traits is challenging as there are limited high-throughput phenotyping methods for roots in the field, and there is a risk that traits selected in the lab on young plants will not translate into mature root system traits in the field. We give an example of a breeding programme that combines laboratory and field phenotyping with proof of concept evaluation of the trait at the beginning of the selection programme. This would greatly enhance confidence in a high-throughput laboratory or field screen, and avoid investment in screens without yield value. This approach requires careful selection of field sites and years that allow expression of deep roots and increased yield. It also requires careful selection and crossing of germplasm to allow comparison of root expression among genotypes that are similar for other traits, especially flowering time and disease and toxicity resistances. Such a programme with field and laboratory evaluation at the outset will speed up delivery of varieties with improved root systems for higher yield.
Assuntos
Cruzamento , Produtos Agrícolas/crescimento & desenvolvimento , Raízes de Plantas/crescimento & desenvolvimento , Característica Quantitativa Herdável , Triticum/crescimento & desenvolvimento , Triticum/metabolismo , Água/metabolismo , Produtos Agrícolas/metabolismo , Raízes de Plantas/genéticaRESUMO
Many rainfed wheat production systems are reliant on stored soil water for some or all of their water inputs. Selection and breeding for root traits could result in a yield benefit; however, breeding for root traits has traditionally been avoided due to the difficulty of phenotyping mature root systems, limited understanding of root system development and function, and the strong influence of environmental conditions on the phenotype of the mature root system. This paper outlines an international field selection program for beneficial root traits at maturity using soil coring in India and Australia. In the rainfed areas of India, wheat is sown at the end of the monsoon into hot soils with a quickly receding soil water profile; in season water inputs are minimal. We hypothesised that wheat selected and bred for high yield under these conditions would have deep, vigorous root systems, allowing them to access and utilise the stored soil water at depth around anthesis and grain-filling when surface layers were dry. The Indian trials resulted in 49 lines being sent to Australia for phenotyping. These lines were ranked against 41 high yielding Australian lines. Variation was observed for deep root traits e.g. in eastern Australia in 2012, maximum depth ranged from 118.8 to 146.3cm. There was significant variation for root traits between sites and years, however, several Indian genotypes were identified that consistently ranked highly across sites and years for deep rooting traits.
RESUMO
Sixty patients with symptomatic duodenal ulcer were randomized to receive either omeprazole (20 mg each morning) or famotidine (40 mg at night time) for 2-4 weeks in a double-blind parallel group clinical trial. Healing rates were higher with omeprazole in comparison with famotidine after 2 weeks (77% vs. 40%, P < 0.001) and 4 weeks (93% vs. 80%, P = 0.2) of treatment. Assessment of daily diary cards completed by all patients revealed that omeprazole rapidly relieved ulcer-related day pain and nocturnal pain in comparison to famotidine. Treatment with omeprazole for 2 weeks was also associated with lower cumulative antacid intake (P < 0.05) and reduced absenteeism from work. Helicobacter pylori infection was present in all patients and remained unaffected by treatment with either of the drugs. None of the drugs produced any significant adverse effects. During 6 months follow-up of all the patients after ulcer healing (without maintenance therapy), ulcer relapse was seen in 40% of omeprazole- and 37% of famotidine-treated patients (P > 0.1). The duration of ulcer-free period following initial healing of ulcer was also similar in both the groups (median time: 22 weeks for omeprazole, 21 weeks for famotidine). We conclude that omeprazole is superior to famotidine in rapidly healing duodenal ulcers and achieving more rapid pain relief, but does not influence subsequent ulcer relapse.
Assuntos
Úlcera Duodenal/tratamento farmacológico , Famotidina/uso terapêutico , Omeprazol/uso terapêutico , Cicatrização/efeitos dos fármacos , Absenteísmo , Adulto , Analgésicos/uso terapêutico , Antiácidos/administração & dosagem , Método Duplo-Cego , Úlcera Duodenal/microbiologia , Úlcera Duodenal/fisiopatologia , Famotidina/efeitos adversos , Feminino , Infecções por Helicobacter/diagnóstico , Helicobacter pylori , Humanos , Masculino , Pessoa de Meia-Idade , Omeprazol/efeitos adversos , Dor/prevenção & controle , RecidivaRESUMO
This paper presents an analytical study on the behaviour of blood flow through an arterial segment having a mild stenosis. The artery has been treated as a thin-walled initially stressed orthotropic non-linear viscoelastic cylindrical tube filled with a non-Newtonian fluid representing blood. The analysis is restricted to propagation of small-amplitude harmonic waves, generated due to blood flow whose wave length is large compared to the radius of the arterial segment. For the equations of motion of the arterial wall consideration is made of a pair of appropriate equations derived by using suitable constitutive relations and the principle of superimposition of a small additional deformation on a state of known finite deformation. It has been shown through numerical computations of the resulting analytical expressions that the resistance to flow and the wall shear increase as the size of the stenosis increases. A quantitative analysis is also made for the frequency variation of the flow rate at different locations of the artery, as well as of the phase velocities and transmission per wavelength.
Assuntos
Arteriopatias Oclusivas/fisiopatologia , Modelos Cardiovasculares , Arteriopatias Oclusivas/patologia , Artérias/patologia , Artérias/fisiopatologia , Velocidade do Fluxo Sanguíneo/fisiologia , Viscosidade Sanguínea/fisiologia , Constrição Patológica/patologia , Constrição Patológica/fisiopatologia , Elasticidade , Humanos , Fluxo Sanguíneo Regional/fisiologia , Reologia , Estresse Mecânico , ViscosidadeRESUMO
High incidence of alpha thalassaemias (estimated from detection of Hb Bart's from cord blood), Hb constant spring (CS) and high A2 beta thalassaemia trait (estimated from normal adult subjects) were detected in 12.6, 15 and 8 per cent people of coastal Orissa (with less than 5% tribal population) respectively. Quantitation of Hb Bart's suggest that the alpha thalassaemia could be any of the genotypes such as, -alpha/alpha alpha, -alpha/-alpha, --/alpha alpha and alpha alpha/alpha alpha cs. Both heterozygotes and homozygotes for Hb CS were identified.
Assuntos
Talassemia/epidemiologia , Sangue Fetal/química , Hemoglobinas Anormais/análise , Humanos , Índia/epidemiologia , Prevalência , Talassemia/genéticaRESUMO
Chronic diarrhoea occurs in several endocrine gland disorders, largely in gut neuro-endocrine tumours, due to the release of various agents into circulation, which affect gastrointestinal function (Table I). In the strict physiological sense, these agents may be hormones (such as gastrin), paracrine substance (somatostatin), neurotransmitters or neuro modulators (vasoactive intestinal polypeptide; VIP) or unknown agent(s) yet to be identified. For each of these syndromes or diseases (Table I), this review considers the characteristics of diarrhoea, its pathogenesis and the therapeutic aspects. The approach to the diagnosis of these syndromes, including localization of tumour tissue and the selection of appropriate anti-tumor treatment are also outlined.
Assuntos
Diarreia/etiologia , Doenças do Sistema Endócrino/complicações , Neoplasias/complicações , Diarreia/fisiopatologia , Diarreia/terapia , HumanosRESUMO
A prospective case controlled study was conducted to evaluate the value of real time ultrasound in establishing the diagnosis and the etiology of portal hypertension. Patients attending the outpatient department of a tertiary care centre were included. There were 324 consecutive patients with portal hypertension due to cirrhosis (n = 229), non cirrhotic portal fibrosis (NCPF: n = 64) and extrahepatic portal venous obstruction (EHPVO: n = 31). During this period, 146 patients with dyspepsia, 35 with splenomegaly and 32 with ascites due to varied causes served as negative and positive controls. Real time ultrasonography using a 3.5 MHz linear array scanner was performed in a fasting state in all subjects. Portal and splenic vein diameter greater than 10 mm, splenomegaly, hepatic and splenic hilar collaterals were suggestive of portal hypertension. Non visualization of the portal vein which was replaced by a cavernoma had a diagnostic accuracy of 98% in EHPVO. Splenic infarcts and absence of ascites were features of non cirrhotic portal hypertension (NCPF and EHPVO). Sonography had an overall diagnostic accuracy of 80%. A stepwise logistic regression with multivariate analysis using discriminate function showed that collaterals at the hepatic and splenic hilum, hepatomegaly, ascites and splenic infarcts were independent markers to differentiate cirrhotic from noncirrhotic causes of portal hypertension. The discriminate equation generated had a mismatch of 9.8%. Correlations between the sonographic signs demonstrated that the variceal grade correlated positively with the presence of splenic hilar collaterals and the liver size inversely correlated with presence of ascites. It was concluded that real time ultrasonography is an accurate method to establish the presence and etiology of portal hypertension.
Assuntos
Hipertensão Portal/diagnóstico por imagem , Adulto , Estudos de Casos e Controles , Circulação Colateral , Varizes Esofágicas e Gástricas/diagnóstico por imagem , Feminino , Humanos , Hipertensão Portal/etiologia , Cirrose Hepática/complicações , Modelos Logísticos , Masculino , Análise Multivariada , Veia Porta/diagnóstico por imagem , Valor Preditivo dos Testes , Estudos Prospectivos , Sensibilidade e Especificidade , Veia Esplênica/diagnóstico por imagem , UltrassonografiaRESUMO
BACKGROUND: We explored the addition of rituximab to high-dose cytarabine (ara-C), oxaliplatin (L-OHP), and dexamethasone [R-DHAOx], in resistant and relapsed patients with CD20-positive follicular non-Hodgkin's lymphoma. METHODS: Twenty-two patients were included; they were treated previously with one to five chemotherapy regimens, including 13 patients who had also received rituximab. R-DHAOx consisted of rituximab, 375mg/m(2), day 1; dexamethasone, 40mg/d, days one to four; L-OHP, 130mg/m(2), day 1; and ara-C, 2000mg/m(2) every 12 h, day 2. Courses were repeated every 21 days for eight courses. RESULTS: Twenty-one patients (95%) achieved a complete response and one had a partial response. Responses were obtained in patients with and without resistance to prior treatment, either alone or combined with rituximab. The median follow-up time was 58.3 months (range, 8.7-92.6 months). Progression-free survival reached a plateau at 84% at 38.2 months. Only two of the 21 complete responders have relapsed. Tumor molecular markers disappeared in all 10 complete responders whose markers were found before treatment. Peripheral neuropathy related to the cumulative dose of L-OHP, and myelosuppression were the most prominent toxic effects. CONCLUSIONS: R-DHAOx is highly active for salvage treatment of patients with follicular non-Hodgkin's lymphoma, and it produces long-term antitumor efficacy.