Alkoxy- and hydroxycyclization of enynes catalyzed by Pd(II) and Pt(II) catalysts

The development of a novel reaction ideal in terms of atom economy was achieved. The scope of the reaction was evaluated in the presence of Pd and Pt catalysts. The first enantioselective Pt-promoted enyne carboalkoxycyclization was developed in up to 85 % stereoselectivity. This ideal atom-economical reaction afforded the corresponding functionalized five-membered carbo- and heterocycles in good to excellent yields. The use of silver salts combined with (R)-Ph-BINEPINE, a monophosphane atropisomeric ligand, was found to be the best-suited combination for moderate to high enantioselectivities on carbonated and nitrogenated substrates

Youth Decision Making in Agricultural Adaptation to Climate Change; An Analysis in East Africa

In conjunction with the contemporary narrative of Africa’s “youth bulge” and young people’s perceived disinterest in pursuing agricultural livelihoods, this paper explores the extent to which youth (18-35 years old) have decision making power in the implementation of agricultural adaptation practices due to climate change in East Africa via the utilization of a comparative political ecology framework. Focus groups discussions, key informant, and individual interviews were conducted with a total of 155 rural youth and 42 policymakers and stakeholder representatives in selected sites in Tanzania, Kenya, and Uganda to assess youth’s knowledge of adaptation measures and their role in the decision to implement them at the household, community, and national levels. Our findings suggest that young people have an understanding of climate change and how to adapt to it. However, they are unable to do so due to lack of agricultural inputs and financial capital, insufficient land ownership, indirect participation in decision making and limited access to markets

Youth Decision Making in Agricultural Climate Change Adaptations: Research findings from East Africa

Africa boasts the world’s most rapid population growth, and is concurrently experiencing a “youth bulge” – an expansion in population of tech-savvy, well-educated, job-ready 18-35 year olds (Population Reference Bureau, 2013). In some cases, a growing youth population is a positive indication of a country’s development, and can be beneficial, as long as the majority of youth are sufficiently employed and contribute to the economy. However, employment can be difficult to find when the job seekers are many and the options are uncertain. The East Africa region is experiencing this “ticking time bomb” at the country level (Ighobor, 2013) within Kenya, Uganda, and Tanzania, with a nagging fear that youth unable to find work may create political and economic instability, resulting in violence (UN, 2013). According to the Youth Development Index (YDI), Kenya is well developed to support its youth population, compared to Uganda and Tanzania. Although it is still ranked “Medium” for the status of young people with a YDI of 0.563, Kenya demonstrated the largest growth in the YDI globally (22%) between 2010 and 2015. Similarly, Uganda has a YDI of 0.544, but supersedes Kenya in the area of employment, with a score of 0.613 compared with Kenya’s 0.513. Tanzania lags far behind both of its neighbors, with a “Low” YDI of .436, and an employment index of 0.294 (Commonwealth Secretariat, 2015). The growing youth population and a stagnant job market in Kenya, Uganda, and Tanzania correlate with a bleak employment outlook. In Kenya, of those who are unemployed, over 70% are under 35 years old. Youth account for two-thirds of Kenya’s population, and the rate of youth who are unemployed may reach as high as 35%, compared to 10% nation-wide (BCtA, 2016). In Uganda, of those who are unemployed, 64% are 24 years old and under (World Bank, 2015). In Tanzania, unemployment averages 13.4% for 15-34 year olds (Youth Employment Decade, 2015). The limited options do not appear to discriminate; youth are simply trying to find a place for themselves, wherever they qualify, whether it is urban, rural, business or farming. Agricultural livelihoods are vital to East Africa, with much of the region’s GDP dependent on agriculture and with arable lands prime for both subsistence and commercial farmers. However, this relationship to agriculture can be risky; in times of success, it provides employment and food security, and in times of misfortune, it contributes to pervasive poverty and malnutrition. For Kenya in particular, 75% of the country’s workforce is in the agricultural sector, contributing to 25% of the country’s GDP, despite only 20% of the land being arable. Kenya’s dominant areas of agriculture are horticultural produce and dairy, which have opportunities to expand; yet Kenya’s agricultural productivity has been stagnant in recent years. For highly arable Uganda, agriculture employs 66% of its labor force, comprises 50% of its exports, and creates 23% of its GDP. The dominant crop for food security is maize, followed by beans, with coffee being the main export, although Uganda has suffered heavy harvest losses in recent years. For Tanzania, while 75% of its population is involved in agriculture, the sector contributes only 31.5% of its GDP. Despite the fact that Tanzania is largely self-sustaining in the staple crop of maize, it lags far behind global average maize yields (Feed the Future, 2016). Although farming is a common livelihood, it is a risky one, with climate change as one of the contributing factors. Farmers in Kenya, Uganda, and Tanzania are heavily dependent on rainfall, and therefore highly vulnerable to inconsistent weather events, such as droughts, floods, intense heat, and severe cold. Such extremities and uncertainties have a negative impact on agriculture, thwarting the involvement of young people. The status of a burgeoning youth population in East Africa, precarious employment opportunities, and the alteration of traditional agricultural practices in the face of climate change has prompted the need to explore the role of youth in adaptive farming practices; specifically, the extent of their decision making power in agricultural adaptations to climate change. This information is critical to understanding the future of agriculture and youth in Kenya, Uganda, and Tanzania

Succession et relève en édition au Québec : étude du processus de transmission dans trois maisons d’édition

Depuis plusieurs années, la question de la relève constitue un sujet d’inquiétude dans de nombreux secteurs d’activité où œuvrent de petites et moyennes entreprises. Le milieu du livre est particulièrement touché par ce problème, alors que près de la moitié des propriétaires de maisons d’édition prévoient prendre leur retraite au cours des dix prochaines années. Or, la question est d’autant plus délicate que la plupart des maisons d’édition fonctionnent avec des ressources limitées et sont dirigées par un individu, l’éditeur, qui cumule la direction de l’entreprise et le contrôle du capital, en plus d’incarner, à la fois, la valeur économique et symbolique de l’entreprise. Même si cette question de la relève dans le milieu éditorial se pose avec autant d’actualité, elle n’a pas encore fait l’objet de travaux spécifiques. Le premier chapitre aborde plusieurs notions théoriques qui nous ont permis de distinguer la nature de ce qui est transmis (ou non) des modalités de la transmission qui sont différentes d’un cas à l’autre. Un arrimage inédit entre concepts managériaux et sociologiques permet de démontrer que le processus de transmission d’une maison d’édition est d’autant plus complexe qu’il est motivé par des enjeux propres aux entreprises œuvrant dans l’économie des biens symboliques. La transmission n’est pas seulement une question de processus, abondamment étudiée par la littérature managériale, mais aussi de stratégies, d’enjeux et d’intérêts spécifiques en fonction des capitaux détenus par les individus impliqués dans des rapports de forces et des luttes pour la légitimité et la reconnaissance. Le deuxième chapitre retrace l’histoire des maisons d’édition au Québec qui ont fait l’objet d’une transmission. Il faut attendre les années 1960 pour que la troisième génération d’éditeurs bénéficie de conditions propices à la transmission grâce à la professionnalisation du métier, au développement de moyens de production et de diffusion, à la croissance d’un lectorat et à la multiplication d’instances de diffusion, de légitimation et de consécration. La seconde partie de la thèse (chapitres 3 à 5) présente l’étude des trois maisons d’édition de littérature générale fondées entre 1960 et 1985 qui constituent notre corpus. Ces entreprises – Hurtubise, Septentrion et XYZ Éditeur – ont été retenues, car elles ont fait l’objet d’un processus de transmission: succession familiale (Hurtubise), relève interne (Septentrion) et vente (XYZ Éditeur). L’analyse met en évidence les conditions, les enjeux et les effets spécifiques de la transmission qui diffèrent selon les entreprises. Selon notre hypothèse, le capital symbolique, acquis par les individus et l’entreprise, a une influence majeure sur le processus de transmission, ce qui oblige les différents acteurs à avoir recours à différentes stratégies – succession, conservation et subversion – pour consolider, maintenir ou transformer leur position et, dans le cas d’entreprises familiales, pour préserver le patrimoine. C’est le cas des Éditions Hurtubise où le processus de transmission est marqué par une stratégie de succession, motivée par une volonté de développement de l’entreprise à travers la mobilisation, puis le transfert entre les générations des ressources (économique, sociale et culturelle et symbolique) détenues par la famille Foulon. Aux Éditions du Septentrion, le recours à une stratégie de conservation s’est imposé au repreneur, Gilles Herman, le temps qu’il acquière la légitimité nécessaire à la direction de l’entreprise et, plus largement, à la reconnaissance dans le champ éditorial. Si des changements sont inévitables, ils s’inscrivent toujours dans la filiation du projet éditorial souhaité par les fondateurs du Septentrion. Enfin, l’acquisition puis l’intégration de XYZ Éditeur au Groupe HMH témoignent d’une stratégie de subversion, marquée par une tension paradoxale entre une volonté de continuité éditoriale – par souci de préservation des acquis économiques et symboliques de la maison –, et une nécessité de rentabilité économique imposées par les acquéreurs

Single-trace clustering power analysis of the point-swapping procedure in the three point ladder of Cortex-M4 SIKE

In this paper, the recommended implementation of the post-quantum key exchange SIKE for Cortex-M4 is attacked through power analysis with a single trace by clustering with the $k$-means algorithm the power samples of all the invocations of the elliptic curve point swapping function in the constant-time coordinate-randomized three point ladder. Because each sample depends on whether two consecutive bits of the private key are the same or not, a successful clustering (with $k=2$) leads to the recovery of the entire private key. The attack is naturally improved with better strategies, such as clustering the samples in the frequency domain or processing the traces with a wavelet transform, using a simpler clustering algorithm based on thresholding, and using metrics to prioritize certain keys for key validation. The attack and the proposed improvements were experimentally verified using the ChipWhisperer framework. Splitting the swapping mask into multiple shares is suggested as an effective countermeasure

Recurrence of heterotopic ossification after removal in patients with traumatic brain injury: A systematic review

AbstractObjectiveA systematic review of the literature to determine whether in patients with neurological heterotopic ossification (NHO) after traumatic brain injury, the extent of the neurological sequelae, the timing of surgery and the extent of the initial NHO affect the risk of NHO recurrence.Data sourcesWe searched MEDLINE via PubMed and Cochrane library for articles published up to June 2015. Results were compared with epidemiological studies using data from the BANKHO database of 357 patients with central nervous system (CNS) lesions who underwent 539 interventions for troublesome HO.ResultsA large number of studies were published in the 1980s and 1990s, most showing poor quality despite being performed by experienced surgical teams. Accordingly, results were contradictory and practices heterogeneous. Results with the BANKHO data showed troublesome NHO recurrence not associated with aetiology, sex, age at time of CNS lesion, multisite HO, or “early” surgery (before 6months). Equally, recurrence was not associated with neurological sequelae or disease extent around the joint.ConclusionsThe recurrence of NHO is not affected by delayed surgery, neurological sequelae or disease extent around the joint. Surgical excision of NHO should be performed as soon as comorbid factors are under control and the NHO is sufficiently constituted for excision

Improving the Performance of Scala Collections with Miniboxing

Using generics, Scala collections can be used to store different types of data in a type-safe manner. Unfortunately, due to the erasure transformation, the performance of generics is degraded when storing primitive types, such as integers and floating point numbers. Miniboxing is a novel translation for generics that restores primitive type performance. Naturally, a good choice would be to use miniboxing to translate Scala collections. In this paper we explore the patterns used to implement the Scala collections, describe how they are transformed by miniboxing and finally compare the performance of the two transformations on a mockup of the Scala collection library. The benchmarks show our prototype implementation (http://scala-miniboxing.org) can speed up collection operations by 45% without any need for programmer intervention

Practical Fault Injection Attacks on SPHINCS

The majority of currently deployed cryptographic public-key schemes are at risk of becoming insecure once large scale quantum computers become practical. Therefore, substitutes resistant to quantum attacks楊nown as post-quantum cryptography預re required. In particular, hash-based signature schemes appear to be the most conservative choice for post-quantum digital signatures. In this work, we mount the first practical fault attack against hash-based cryptography. The attack was originally proposed by Castelnovi, Martinelli, and Prest [9] and allows the creation of a universal signature forgery that applies to all current standardisation candidates (XMSS, LMS, SPHINCS+, and Gravity-SPHINCS). We perform the attack on an Arduino Due board featuring an ARM Cortex-M3 microprocessor running the original stateless scheme SPHINCS with a focus on practicality. We describe how the attack is mountable with a simple voltage glitch injection on the targeted platform, which allowed us to collect enough faulty signatures to create a universal forgery within seconds. As the attack also applies to stateful schemes, we show how caching one-time signatures can entirely prevent the attack for stateful schemes, such as XMSS and LMS. However, we discuss how protecting stateless schemes, like SPHINCS, SPHINCS+, and Gravity-SPHINCS, is more challenging, as this countermeasure does not apply as efficiently as in stateful schemes

SIKE Channels

We present new side-channel attacks on SIKE, the isogeny-based candidate in the NIST PQC competition. Previous works had shown that SIKE is vulnerable to differential power analysis and pointed to coordinate randomization as an effective countermeasure. We show that coordinate randomization alone is not sufficient, as SIKE is vulnerable to a class of attacks similar to refined power analysis in elliptic curve cryptography, named zero-value attacks. We describe and confirm in the lab two such attacks leading to full key recovery, and analyze their countermeasures

Troublesome Heterotopic Ossification after Central Nervous System Damage: A Survey of 570 Surgeries

BACKGROUND: Heterotopic ossification (HO) is a frequent complication after central nervous system (CNS) damage but has seldom been studied. We aimed to investigate features of HO for the first time in a large sample and the rate of early recurrence of HO in terms of the time of surgery. METHODOLOGY/PRINCIPAL FINDINGS: We retrospectively analyzed data from an anonymous prospective survey of patients undergoing surgery between May 1993 and November 2009 in our institution for troublesome HO related to acquired neurological disease. Demographic and HO characteristics and neurological etiologies were recorded. For 357 consecutive patients, we collected data on 539 first surgeries for HO (129 surgeries for multiple sites). During the follow-up, recurrences requiring another surgery appeared in 31 cases (5.8% [31/539]; 95% confidence interval [CI]: 3.8%-7.8%; 27 patients). Most HO requiring surgery occurred after traumatic brain injury (199 patients [55.7%]), then spinal cord injury (86 [24.0%]), stroke (42 [11.8%]) and cerebral anoxia (30 [8.6%]). The hip was the primary site of HO (328 [60.9%]), then the elbow (115 [21.3%]), knee (77 [14.3%]) and shoulder (19 [3.5%]). For all patients, 181 of the surgeries were performed within the first year after the CNS damage, without recurrence of HO. Recurrence was not associated with etiology (p = 0.46), sex (p = 1.00), age at CNS damage (p = 0.2), multisite localization (p = 0.34), or delay to surgery (p = 0.7). CONCLUSIONS/SIGNIFICANCE: In patients with CNS damage, troublesome HO and recurrence occurs most frequently after traumatic brain injury and appears frequently in the hip and elbow. Early surgery for HO is not a factor of recurrence