The first novel in Xhosa

The first novel in the Xhosa language, USamson, written by the greatest figure in the history of Xhosa literature, S. E. K. Mqhayi (1875–1945), and published in 1907, is now lost. It was produced at a time when black people in South Africa were becoming bolder in their demand for human rights, forming independent black churches and political organizations. It appeared after a period of gestation for Xhosa literature in newspapers, at a time when missionaries were discussing the publication of books in Xhosa, but Mqhayi paid for its printing and organized its distribution. The novelette added details of setting and characterization to the biblical story to encourage the youth to gather behind black leaders who lacked support. Caught in the social tension between Xhosa and Mfengu, USamson was heavily criticized by I. W. Wauchope for departing from biblical narrative, but more generally defended by readers, who looked forward to the further publication of Xhosa literature in books

Heterogeneous Productivity in Voluntary Public Good Provision: an Experimental Analysis

This article experimentally examines voluntary contributions when group members’ marginal returns to the public good vary. The experiment implements two marginal return types, low and high, and uses the information that members have about the heterogeneity to identify the applied contribution norm. We find that norms vary with the information environment. If agents are aware of the heterogeneity, contributions increase in general. However, high types contribute more than low types when contributions can be linked to the type of the donor but contribute less otherwise. Low types, on the other hand, contributes more than high types when group members are aware of the heterogeneity but contributions cannot be linked to types. Our results underline the importance of the information structure when persons with different abilities contribute to a joint project, as in the context of teamwork or charitable giving.Public Goods, Voluntary contribution mechanism, Heterogeneity, Information, Norms

Heterogeneous Productivity in Voluntary Public Good Provision: An Experimental Analysis

This article experimentally examines voluntary contributions when group members' marginal returns to the public good vary. The experiment implements two marginal return types, low and high, and uses the information that members have about the heterogeneity to identify the applied contribution norm. If agents are aware of the heterogeneity, contributions increase in general. However, high types contribute more than low types when contributions can be linked to the type of the donor but contribute less otherwise. Low types, on the other hand, contribute more than high types when group members are aware of the heterogeneity but contributions cannot be linked to types. Our results underline the importance of the information structure when persons with different abilities contribute to a joint project, as in the context of teamwork or charitable giving.public goods, voluntary contribution mechanism, heterogeneity, information, norms

Aggregation Problems in Estimates of Armington Elasticities and Pass-Through Effects

This article examines the level of aggregation problem for which Armington price elasticity of substitution and pass-through effects are usually estimated. On the basis of U.S. import data from 1995 to 2004 of wood products from Brazil and Mexico, it is argued that the usuallevels of aggregation used in the estimates for the elasticity of substitution are too high, since they tend to aggregate perfectly elastic products together with products whose elasticities vary from zero to any negative number. Analogously, the elasticity of relative prices with respect to the exchange rate, a measure of the pass-through effect, tends to be underestimated in the U.S. by the presence of homogeneous products whose prices are set in dollars and tend to equalize through arbitrage. Therefore, pricing-to-market estimates may be grossly overestimated for some industries in the U.S.Homogeneous Products, Differentiated Product, Pass-Through, Pricing-to-Market, Law of One Price

EFEKTIVITAS KOMBINASI DL-αTOKOFEROL DAN ASAM ASKORBAT TERHADAP KADAR LDL-OX, sCD36, sVCAM-1 DAN NO PADA ANAK SINDROM NEFROTIK

Latar Belakang: Stres oksidatif, disfungsi endotel dan inflamasi mendasari proses aterosklerosis pada anak sindrom nefrotik (SN). Kombinasi dl-α-tokoferol dan asam askorbat berpotensi menurunkan proses stress oksidatif dan disfungsi endotel banyak diteliti pada orang dewasa namun terbatas pada anak SN. Tujuan: Membuktikan pengaruh pemberian kombinasi dl-α-tokoferol dan asam askorbat terhadap Δ kadar LDL-ox sebagai marker stress oksidatif, reseptor makrofag sCD36, sVCAM-1 dan NO sebagai biomarker disfungsi endotel pada anak SN usia 1 – 15 tahun. Metode: Randomized pre test-post test control group design dilakukan pada anak SN usia 1- 15 tahun selama 12 minggu. Kelompok perlakuan diberi obat standar (prednison dosis penuh) dan kombinasi dl-α-tokoferol 10-15 mg /kg/hari & asam askorbat dengan dosis sama, dibagi 2 dosis secara oral. Kelompok kontrol menerima obat standar dan plasebo. Variabel LDL-ox, sCD36, sVCAM-1 diperiksa secara ELISA, NO secara kolorimetri. Analisis statistik digunakan uji Wilcoxon, uji t tidak berpasangan/Mann-Whitney U. Hasil: Rerata pretest-posttest kelompok perlakuan kadar LDL-ox (127,2 menjadi 89,5 U/L); sVCAM-1:(929,4 menjadi 868,4ng/mL); NO: (8,9 menjadi 8,5μM/L) menurun. Kadar sCD36 (72,5 menjadi 123,5 ng/mL) meningkat. Kelompok kontrol: LDL-ox (125,2 menjadi 76,7 U/L), sVCAM-1(1231,2 menjadi 1008,0 ng/mL), NO (8,2 menjadi 7,9μM) menurun,. sCD36(56,9 menjadi 61,7ng/mL) meningkat. Uji Wilcoxon kelompok perlakuan dan kontrol berturut-turut kadar LDL-ox p =0,039 dan 0,001, kadar sCD36 : p=0,163 & 0,088, sVCAM-1: p=0,306 & 0,122 dan NO: p=0,983 & 0,760. Δ LDL-ox -37.7 vs - 48.6U / L ; Δ sCD36: 51.1vs 17,2ng / mL; Δ sVCAM-1: -61.0 vs –223ng /mL ; ΔNO -0.4 vs- 0.6 mg/dL dengan uji beda berturut-turut p = 0,594; 0,327; 0,883; 0,864. Berdasarkan status remisi, uji beda kadar LDL-ox, Δ kadar LDL-ox dan kadar sVCAM-1 post test pada kelompok perlakuan berbeda bermakna dengan p=0,016; 0,047 dan 0,000. Kesimpulan: Pemberian kombinasi dl-α-tokoferol dan asam askorbat dosis 10-15 mg/kgBB/hari selama 12 minggu efektif menurunkan kadar stres oksidatif dan disfungsi endotel pada kelompok perlakuan yang remisi, tetapi tidak efektif terhadap Δ kadar LDL-ox, Δ sCD36, Δ sVCAM-1 dan Δ NO di antara dua kelompok. Kata kunci: Sindrom nefrotik, anti oksidan, stress oksidatif, disfungsi endotel Background: Oxidative stress, endothelial dysfunction and inflammation contribute to early atherosclerosis process in neprotic syndrome (NS). Administration of combination dl-α-tocopherol and ascorbic acid are potential in decreasing oxidative stress and endothelial dysfunction, investigated in adult but not yet in children. Objective: To prove that combined supplementation of dl-α-tocopherol and ascorbic acid on serum levels of oxidized LDL (ox-LDL), soluble scavenger receptor of macrophage CD36(sCD36), soluble vascular cellular adhesion molecule (sVCAM-1) and nitric oxide (NO) level in NS of 1- 15 years old. Methods: A randomized pre test–post test control group design was done for 12 weeks. Treatment group was given standard therapy and dl-α-tocopherol 10 -15 mg/kgBW/day plus ascorbic acid in the same dose, twice daily orally. Control group was given steroid therapy (standard) and placebo. Serum level of ox-LDL, sCD36, sVCAM-1 were measured by ELISA and NO by colorimetri. Analysis was done by Wilcoxon, independent t test or Mann-Whitney U test. Results: The mean level of pre and posttest of ox-LDL (127.2 to 89.5 U/L), sVCAM-1(929.4 to 868.4 ng/mL) and NO (8.9 to 8.5 μM/L) were decreased, but the level of sCD36 (72.5 to 123.5 ng/mL) increased in the treatment group. In control group, the mean level of ox-LDL(125.2 to 76.7 U/L), sVCAM-1(1231.2 to 1008.0 ng/mL), NO ( 8.2 to 7.9 μM) were decreased, but sCD36 (56.9-61.7 ng/mL) was increased. The Wilcoxon test of ox-LDL levels showed p :0.039 in treatment group and p=0.001 in control group. P value in treatment and control group of sCD36 levels were 0.163 and 0.088; sVCAM-1 levels p value = 0.306 & 0.122 and NO levels were p value =0.983 and 0.760. The Δ level of ox-LDL on treatment group compared to control was -37.7vs - 48.6U/L ; Δ sCD36: 51.1vs 17.2ng/mL; Δ sVCAM-1: -61.0 vs –223ng/mL ; Δ NO: -0.4 vs -0.6mg/dL. P value of Δ ox-LDL, ΔsVCAM-1, Δ sCD36 , ΔNO were 0.594, 0.327, 0.883, 0.864, respectively. According to remission state at the end of the study p value level of ox-LDL, Δ ox-LDL and level of sVCAM-1 in treatment group were 0,016; 0,047 and 0,000 respectively. Conclusions: Combined supplementation of dl-α-tocopherol and ascorbic acid 10 –15 mg/kgBW/day for 12 weeks decreased of stress oxidative and endothelial disfunction biomarker in remission state of the treatment group but did not effective to decrease level of Δ ox-LDL, Δ sCD36, Δ sVCAM –1 and Δ NO between two groups. Keywords: Nephrotic syndrome, antioxidant, oxidative stress, endothelial dysfunctio

On the alleged simplicity of impure proof

Roughly, a proof of a theorem, is “pure” if it draws only on what is “close” or “intrinsic” to that theorem. Mathematicians employ a variety of terms to identify pure proofs, saying that a pure proof is one that avoids what is “extrinsic,” “extraneous,” “distant,” “remote,” “alien,” or “foreign” to the problem or theorem under investigation. In the background of these attributions is the view that there is a distance measure (or a variety of such measures) between mathematical statements and proofs. Mathematicians have paid little attention to specifying such distance measures precisely because in practice certain methods of proof have seemed self- evidently impure by design: think for instance of analytic geometry and analytic number theory. By contrast, mathematicians have paid considerable attention to whether such impurities are a good thing or to be avoided, and some have claimed that they are valuable because generally impure proofs are simpler than pure proofs. This article is an investigation of this claim, formulated more precisely by proof- theoretic means. After assembling evidence from proof theory that may be thought to support this claim, we will argue that on the contrary this evidence does not support the claim