Proportion of ripe fruit weight and volume to green coffee: differences in 43 genotypes of Coffea canephora.

The processing yield or performance, which includes drying and depulping of coffee fruits, can be calculated as the relationship between the volume of ripe coffee fruits and green coffee weight and is a relevant characteristic for the development of new cultivars. The purpose of this study was to evaluate the processing performance of 42 genotypes and one population of Coffea canephora. The treatments consisted of 42 C. canephora genotypes propagated by cuttings and one seed-derived population arranged in a randomized block design with three replications. The genotypes were harvested when 80% of the fruits were in the ripe stage (red berries). We evaluated the relationship of the volume to weight of ripe fruit (ripe fruit volume [RFV]/ripe fruit weight [RFW]), the percentage of seed per fruit (% of seeds), the yield (in liters of ripe coffee) required to produce a 60-kg bag of green coffee, and the relationship between RFW and dry green bean weight (RFW/dry seed weight [DSW]). The results were subjected to ANOVA, and the means were grouped by the Scott-Knott test (p < .05). The mean yield of the evaluated genotypes was 347.57 L bag-1 of green coffee (between 294.01 and 439.72 L bag-1). A lower seed per fruit percentage identifies genotypes with a lower yield and higher RFW/DSW ratio. The genotypes Z21, 700, AD1, LB1, Emcapa 143, and AP required less than 315 L of ripe coffee to produce one 60-kg bag of green coffee beans

Transcriptomic analysis supports similar functional roles for the two thymuses of the tammar wallaby

Background: The thymus plays a critical role in the development and maturation of T-cells. Humans have a single thoracic thymus and presence of a second thymus is considered an anomaly. However, many vertebrates have multiple thymuses. The tammar wallaby has two thymuses: a thoracic thymus (typically found in all mammals) and a dominant cervical thymus. Researchers have known about the presence of the two wallaby thymuses since the 1800s, but no genome-wide research has been carried out into possible functional differences between the two thymic tissues. Here, we used pyrosequencing to compare the transcriptomes of a cervical and thoracic thymus from a single 178 day old tammar wallaby.Results: We show that both the tammar thoracic and the cervical thymuses displayed gene expression profiles consistent with roles in T-cell development. Both thymuses expressed genes that mediate distinct phases of T-cells differentiation, including the initial commitment of blood stem cells to the T-lineage, the generation of T-cell receptor diversity and development of thymic epithelial cells. Crucial immune genes, such as chemokines were also present. Comparable patterns of expression of non-coding RNAs were seen. 67 genes differentially expressed between the two thymuses were detected, and the possible significance of these results are discussed.Conclusion: This is the first study comparing the transcriptomes of two thymuses from a single individual. Our finding supports that both thymuses are functionally equivalent and drive T-cell development. These results are an important first step in the understanding of the genetic processes that govern marsupial immunity, and also allow us to begin to trace the evolution of the mammalian immune system

Magnetic dimerization in the frustrated spin ladder Li 2 Cu 2 O ( SO 4 ) 2

International audienceThe magnetic properties of Li 2 Cu 2 O(SO 4) 2 are investigated in the framework of density functional theory. In its high-temperature tetragonal structure, this compound appears as a rare material realization of a frustrated spin-1/2 two-leg ladder, where magnetic frustration arises from competing nearest and next-nearest interactions along the legs. Through a large magnetoelastic coupling, the triclinic distortion occurring around 125 K is shown to induce the formation of a staggered dimer structure, lifting most of the magnetic frustration. During the last few decades, a considerable effort has been devoted to the experimental and theoretical investigation of frustrated quantum antiferromagnets [1]. Among the different models studied as potential candidates in which new states of matter could occur, the frustrated S = 1/2 two-leg spin ladder has received considerable attention, as it combines low spin, low dimensionality, and magnetic frustration. The general Hamiltonian for this model can be written as H = J α=1,2 i S α,i · S α,i+1 + J ⊥ i S 1,i · S 2,i + J × i (S 1,i · S 2,i+1 + S 1,i+1 · S 2,i) + J 2 α=1,2 i S α,i · S α,i+2 , (1) where the index α distinguishes left and right legs, i labels rungs, and the S α,i are the S = 1/2 operators at the rung i on the α th leg of the ladder. J is the nearest-neighbor (NN) exchange coupling along the legs and J ⊥ the interleg coupling along the rungs. Frustration arises either through the next-nearest-neighbor (NNN) coupling along the legs J 2 or through the diagonal, interleg coupling J ×. In the absence of next-nearest-neighbor coupling (J 2 = 0), the phase diagram for this model was originally shown to consist of two parts: a Haldane and a rung-singlet phase [2–4]. It was later suggested that this picture might be incomplete and that an additional, intermediate dimerized phase could also occur [5,6]. Vekua and Honecker [7] further showed that the addition of sufficiently strong next-nearest-neighbor couplings along the legs (J 2 = 0) stabilizes additional columnar dimer and staggered dimer phases. A rich phase diagram thus emerges from this quasi-one-dimensional (quasi-1D) lattice model depending critically on the relative signs and strengths of the various exchange couplings. Unfortunately, only a very limited number of material systems can be considered as true realizations of frustrated S = 1/2 two-leg spin ladders and thus, provide experimental * [email protected] evidence to be confronted by these theoretical predictions. Whereas SrCu 2 O 3 [8] or Sr 14 Cu 24 O 41 [9,10] are prototypical realizations of nonfrustrated ladders, BiCu 2 PO 6 [11] might appear as one of the very rare examples of S = 1/2 frustrated spin ladder where the frustration arises only from NNN interactions along the legs [12]. In this Rapid Communication, we show that the newly synthesized compound Li 2 Cu 2 O(SO 4) 2 [13] is an actual realization of S = 1/2 frustrated two-leg spin ladder. Moreover, we demonstrate that the tetragonal to triclinic structural transition occurring around 125 K [14] leads to the emergence of a staggered S = 1/2 dimer structure, lifting most of the magnetic frustration. The crystal structure of Li 2 Cu 2 O(SO 4) 2 at room temperature is shown in Figs. 1(a) and 1(b). This compound crystallizes in a tetragonal structure, with space group P 4 2 /m where Cu 2+ ions occupy a slightly distorted square planar environment, as commonly observed for this strong Jahn-Teller ion. The resulting CuO 4 squares are grouped by two, sharing an edge to form Cu 2 O 6 platelets. These platelets are connected one to each other through an oxygen atom, after being rotated by 90 • under the effect of the 4 2 helical axis leading to infinite Cu 2 O 5 chains running along the c axis of the crystal [see Fig. 1(b)]. Tetrahedral SO 4 units further link every second platelet along the chains by sharing two oxygen ions with them. These chains are finally separated from each other by the Li + ions. From a magnetostructural perspective, dominant magnetic couplings should occur in this structure either through intra-[J ⊥ in Fig. 1(c)] or interplatelets (J = J ×) Cu-O-Cu superexchange mechanisms or through longer ranged interactions via the nonmagnetic bridging SO 4 units (J 2), as such polyanionic groups are known to be efficient media for magnetic interactions [15]. As additional interchain interactions are expected to be weak due to the absence of well-defined covalent superexchange paths, this compound should exhibit a strong quasi-1D character. Note that the resulting geometry for such an isolated chain maps exactly on a S = 1/2 frustrated two-leg ladder described by (1) in the special case where J = J × as illustrated in Fig. 1(d). Figure 2 shows the paramagnetic band structure and density of states (DOS) of Li 2 Cu 2 O(SO 4) 2 calculated close to the Fermi level. These density functional theory (DFT) 2469-9950/2017/96(18)/180406(5) 180406-

L’atelier di pedagogia dell’emergenza: il caso Afghanistan. Una prima prassi di engagement sociale a partire dalle voci dei protagonisti

L’articolo presenta il primo di una serie di “Atelier di pedagogia dell’emergenza” organizzato dall’Università del Salento con la collaborazione dell’Università Roma Tre e dell’Università dell’Aquila e con la partecipazione del fondatore della ONG PenPath operativa in Afghanistan e da qui collegato. L’iniziativa è stata realizzata per proporre e verificare l’efficacia e la funzionalità di un format pensato nel contesto del gruppo di lavoro sulla Pedagogia dell’emergenza della Siped. L’iniziativa ha inteso integrare la dimensione più tradizionalmente seminariale di approfondimento e divulgazione di tematiche educative con quella dell’apertura di uno spazio-tempo di contatto diretto e vivo con i soggetti e le realtà in emergenza. Grazie al loro intervento diretto si è inteso focalizzare specifiche tematiche che, particolarmente sentite nel contesto in emergenza, sono però di rilevante interesse generale. Tre, dunque, i passaggi centrali del presente contributo: 1) la precisazione, nel primo paragrafo, dell’orizzonte formale (le lenti con le quali guardare il fenomeno oggetto dell’Atelier in more pedagogico) e, dunque, la precisazione dell’opportunità di pensare e impegnarsi in un campo di riflessione e pratica pedagogica intitolati specificatamente all’emergenza; 2) la definizione, nel secondo paragrafo, di un modello rivedibile e implementabile per la realizzazione dell’incontro dove centrali sono la presenza di testimonianze, documentazioni, spaccati di vita in emergenza, non meno che l’attivazione di sistemi di monitoraggio dell’esperienza da parte degli utenti finali; 3) la centratura, a partire anche dal quadro istituzionale di azione dei testimoni privilegiati (paragrafo tre), di focalizzate tematiche (questioni di genere ed educazione delle bambine) di particolare rilievo non solo per il contesto ospitato ma anche, per trasposizione, per realtà a noi più prossime (paragrafo quattro) e comunque non estranee alle questioni trattate per lo specifico contesto in emergenza.The article presents the first “Emergency pedagogy atelier” organized by the University of Salento with the collaboration of the Roma Tre University and the University of L’Aquila and with the participation of the founder of the NGO PenPath operating in Afghanistan and connected from here. The initiative was created to propose and verify the effectiveness and functionality of a format conceived in the context of the Siped Emergency Pedagogy working group. The initiative aimed to integrate the more traditionally seminar dimension of in-depth study and dissemination of educational issues with that of the opening of a space-time of direct and live contact with subjects and realities in emergency. Thanks to their direct intervention, it was intended to focus on specific issues which, particularly felt in the context of an emergency, are however of significant general interest. Three, therefore, the central passages: 1) the clarification, in the first paragraph, of the formal horizon (the lenses with which to look at the phenomenon covered by the Pedagogical Atelier in more) and, therefore, the specification of the opportunity to think and engage in a field of reflection and pedagogical practice specifically dedicated to emergency; 2) the definition, in the second paragraph, of a revisable and implementable model for the realization of the meeting where the presence of testimonies, documentation, glimpses of life in an emergency, as ell as the activation of systems for monitoring the experience by end users; 3) the centering, also starting from the institutional framework of action of privileged witnesses (paragraph three), of focused themes (gender issues and education of girls) of particular importance not only for the hosted context but also, for transposition, for reality closest to us (paragraph four) and in any case not unrelated to the issues dealt with for the specific context in emergency

Relativistic stellar clusters: equilibrium models with anisotropic momentum distribution and dynamic and thermodynamic stability of isotropic models

Models of spherically symmetric relativistic stellar clusters with anisotropic distribution functions in relativistic regime are described by using Maxwellian distribution function with energy cutoff. We consider distributions with different levels of anisotropy and discuss some general characteristics of the models. In addition, we analyze dynamic and thermodynamic stability of isotropic models still described by Maxwellian distribution function with energy cutoff and we find critical values of the onset of instability