Seed potato quality improvement through positive selection by smallholder farmers in Kenya

In Kenya, seed potato quality is often a major yield constraint in potato production as smallholder farmers use farm-saved seed without proper management of seed-borne pests and diseases. Farm-saved seed is therefore often highly degenerated. We carried out on-farm research to assess whether farmer-managed positive seed selection could improve yield. Positive selection gave an average yield increase in farmer-managed trials of 34%, corresponding to a 284-€ increase in profit per hectare at an additional production cost of only 6€/ha. Positive selection can be an important alternative and complementary technology to regular seed replacement, especially in the context of imperfect rural economies characterized by high risks of production and insecure markets. It does not require cash investments and is thus accessible for all potato producers. It can also be applied where access to highquality seed is not guaranteed. The technology is also suitable for landraces and not recognized cultivars that cannot be multiplied formally. Finally, the technology fits seamlessly within the seed systems of Sub-Saharan Africa, which are dominated by self-supply and neighbour supply of seed potatoes

Studi Kelayakan LKS Praktikum Berbasis Pendekatan Saintifik Serta Dampaknya pada Hasil Belajar Materi Sifat Larutan Penyangga

Penelitian ini bertujuan untuk mengetahui kelayakan produk LKS praktikum berbasis pendekatan saintifik dan mengetahui dampaknya pada hasil belajar khususnya  materi sifat larutan penyangga dengan melihat seberapa banyak siswa yang mencapai  atau melampaui KKM. Jenis penelitian ini adalah penelitian dan pengembangan yang dilakukan di kelas XI IPA 5 SMAN 1 Tondano. Berdasarkan hasil rekapitulasi, LKS praktikum berbasis pendekatan saintifik dinyatakan valid dengan nilai sebesar 83,8%. Dilihat dari respon siswa pada uji coba kelompok kecil dan kelompok besar LKS dinyatakan praktis dengan nilai berturut-turut sebesar 88,17% dan 92,98%. Dampak penggunaan LKS terhadap hasil belajar siswa adalah sebagian besar siswa pada uji coba kelompok kecil dan siswa pada uji coba kelompok besar telah melampaui KKM yang sudah ditetapkan dengan nilai ketuntasan yang diperoleh berturut-turut sebesar 66,67% dan 89,47%. Pengujian hipotesis untuk hasil belajar menggunakan uji t pihak kiri diperoleh nilai thitung(8,517) > ttabel(1,734) yang berarti terima H0 atau tolak H1. Berdasarkan hasil yang diperoleh dapat disimpulkan bahwa LKS praktikum berbasis pendekatan saintifik yang dikembangkan layak digunakan dalam proses pembelajaran

Structure-guided design and optimization of small molecules targeting the protein-protein interaction between the von hippel-lindau (VHL) E3 ubiquitin ligase and the hypoxia inducible factor (HIF) alpha subunit with in vitro nanomolar affinities

E3 ubiquitin ligases are attractive targets in the ubiquitin-proteasome system, however, the development of small-molecule ligands has been rewarded with limited success. The von Hippel-Lindau protein (pVHL) is the substrate recognition subunit of the VHL E3 ligase that targets HIF-1α for degradation. We recently reported inhibitors of the pVHL:HIF-1α interaction, however they exhibited moderate potency. Herein, we report the design and optimization, guided by X-ray crystal structures, of a ligand series with nanomolar binding affinities

IFNβ Protects Neurons from Damage in a Murine Model of HIV-1 Associated Brain Injury.

Infection with human immunodeficiency virus-1 (HIV-1) causes brain injury. Type I interferons (IFNα/β) are critical mediators of any anti-viral immune response and IFNβ has been implicated in the temporary control of lentiviral infection in the brain. Here we show that transgenic mice expressing HIV-1 envelope glycoprotein 120 in their central nervous system (HIVgp120tg) mount a transient IFNβ response and provide evidence that IFNβ confers neuronal protection against HIVgp120 toxicity. In cerebrocortical cell cultures, neuroprotection by IFNβ against gp120 toxicity is dependent on IFNα receptor 1 (IFNAR1) and the β-chemokine CCL4, as IFNAR1 deficiency and neutralizing antibodies against CCL4, respectively, abolish the neuroprotective effects. We find in vivo that IFNβ mRNA is significantly increased in HIVgp120tg brains at 1.5, but not 3 or 6 months of age. However, a four-week intranasal IFNβ treatment of HIVgp120tg mice starting at 3.5 months of age increases expression of CCL4 and concomitantly protects neuronal dendrites and pre-synaptic terminals in cortex and hippocampus from gp120-induced damage. Moreover, in vivo and in vitro data suggests astrocytes are a major source of IFNβ-induced CCL4. Altogether, our results suggest exogenous IFNβ as a neuroprotective factor that has potential to ameliorate in vivo HIVgp120-induced brain injury

Intramedullary non-specific inflammatory lesion of thoracic spine: A case report

<p>Abstract</p> <p>Background</p> <p>There are several non-neoplastic lesions which mimick intramedullary spinal cord neoplasm in their radiographic and clinical presentation. These can be classified as either infectious (TB, fungal, bacterial, parasytic, syphilis, CMV, HSV) and non-infectious (sarcoid, MS, myelitis, ADEM, SLE) inflammatory lesions, idiopathic necrotizing myelopathy, unusual vascular lesions and radiation myelopathy. Although biopsy may be indicated in many cases, an erroneous diagnosis of intramedullary neoplasm can often be eliminated pre-operatively.</p> <p>Case description</p> <p>the authors report a very rare case of intramedullary non-specific inflammatory lesion of unknown origin, without signs of infection or demyelinization, in a woman who showed no other evidence of systemic disease.</p> <p>Conclusions</p> <p>Intramedullary lesions that mimick a tumor can be various and difficult to interpret. Preoperative MRI does not allow a certain diagnosis because these lesions have a very similar signal intensity pattern. Specific tests for infective pathologies are useful for diagnosis, but histological examination is essential for establishing a certain diagnosis. In our case the final histological examination and the specific tests that we performed have not cleared our doubts regarding the nature of the lesion that remains controversial.</p