Passive adaptation or active engagement? The challenges of Housing First internationally and in the Italian case

In recent years, a peculiar homelessness policy that goes under the name of ‘Housing First’ has become increasingly popular all over the world. Epitomising a quintessential case of policy-mobility, Housing First can today be considered an heterogeneous assemblage of experiences and approaches that sometimes have little in common with each other. Introducing and commenting upon this heterogeneity, the paper critically analyses why and how Housing First has become a planetary success and what are the issues at stake with its widespread implementation. If recent scholarship published in this journal has granted us a fine understanding of Housing First’s functioning in the US, this paper offers something currently absent from the debate: a nuanced and critical understanding of the ambiguities related to the international success of this policy, with specific references to the challenges associated to its translation in the Italian case.     

Genetic and genomic analysis of age at first insemination in Israeli dairy cattle

We performed a genetic analysis of age at first insemination, including estimation of the heritability and genetic correlations with other economic traits, and the consequences of including this trait in the Israeli selection index. The genetic factors affecting age at first insemination were determined via GWAS. Five data sets were analyzed. Data sets 1, 2, and 3 were used to compute variance components among age at first insemination, first calving age, days from first insemination to calving, and the 9 traits included in the Israel breeding index. Heritabilities for age at first insemination, calving age, and days from first insemination to calving in Israeli Holsteins as computed by REML individual animal model analyses of 273,239 Israeli Holstein cows were 0.072, 0.042, and 0.014. The estimated genetic correlation between the first 2 traits was 0.88. In addition to the fact that heritability of age at first insemination is 1.7 times the heritability for calving, the former trait has the advantage that the number of records is greater, and the records are generated earlier. Absolute values of the genetic and residual correlations between age at first insemination and the 9 traits included in the Israeli index were all less than 0.2. Data set 4 included first insemination dates of 1,181,600 calves born from 1985 through 2018. Genetic evaluations were computed by a single trait animal model. Annual phenotypic and genetic trends for age at first calving for calves born since 1985 were “positive,” that is, economically negative, at 0.320 ± 0.003 and 0.169 ± 0.005 d, respectively. Applying the GCTA-GREML software, 54% of variance in the transmitting ability of 1,585 sires could be explained by considering all 40,498 markers included in the GWAS analysis. The significant markers were mainly associated with milk production genes. The SNP UA-IFASA-8854 on chromosome 11 had the lowest probability value, 1.2 × 10^?24. This marker is located between the genes RETSAT and ELMOD3, both of which are overexpressed in human mammary glands. The gene RETSAT is reported to be essential for lipid accumulation and adipogenesis promotion. Gene enrichment analysis found that genes in the genomic region flanking significant markers are associated with vasopressin receptor activity, which was shown to mediate puberty in humans. If age at first insemination is included in the index with a weighting to account for 9% of the index, reductions of 2.8 and 2.6 d for age at first insemination and first calving age after 10 yr of selection are predicted, as compared with reductions of 1.4 and 1.1 d with the current index. Gains for the other index traits are only marginally affected. We suggest selection on age at first insemination as an alternative to selection for early calving.     

一种基于业务区分的随机接入方案

通过对移动通信系统关键技术的发展趋势和网络实时业务服务质量（QoS）需求的分析,提出了一种适用于时分－正交频分多址接入系统（TD-OFDMA）的简单高效的随机接入方案。在该方案中,网络终端利用特有的优先随机接入信道（FRRACH）对不同时延特性的业务采用不同的随机接入机制,从而有效地避免分组碰撞,保障实时业务的QoS需求。理论分析和仿真结果表明,该方案在成功接入概率、接入时延以及资源利用率等方面的性能较目前常用的随机接入方案有着较大的改善。     

薄煤层坚硬顶板的薄板理论分析及来压预报

在用薄板理论分析白腊坪煤矿K13煤层顶板的应力分布规律的基础上，根据最大拉应力强度理论建立顶板初次及周期来压步距的计算式，利用该计算式在现场实施顶板来压预报结果表明，用薄板理论研究薄煤层坚硬顶板的应力分布规律是合理的。     

淮南市大气颗粒物时空变化特征及成因探讨

淮南是以煤电化为支柱产业的典型能源城市,大气结构性污染十分突出.伴随煤电化"三大基地"与"生态淮南"建设,城市大气环境质量调查研究及预测对实施有效环境管理十分必要.在系统统计淮南市大气颗粒物监测数据基础上,综合剖析了城市多年降尘和TSP的年均值时空分布特征,探讨了大气颗粒物污染成因.     

急倾斜特厚煤层综放工作面超段高初次放顶的实践

介绍了采区概况及初次放顶的方案选择 ,并详细说明了实施放顶的步骤及放顶过程中相关措施 ,实际应用中效果良好。     

晋煤集团高瓦斯矿井煤层气抽采及利用效果

介绍了晋城煤业集团煤层气储量及赋存特点,阐述了"先抽后采"、采煤采气一体和"三级"瓦斯治理的模式、方法及配套抽采方式和工艺。重点叙述了"井上下抽采相结合,井上抽采先行;抽采利用相结合,以用促采",开创了高瓦斯矿井煤层气抽采利用新局面。     

深部首采工作面顶底板涌水量预计

在深部工作面受多种含水体影响的情况下,通过对工作面采矿地质条件深入研究,根据综放开采条件下覆岩破坏和底板下"三带"的经验公式,预计了开采对顶底板造成破坏的范围,对各含水层向工作面充水危险进行了分析。参考类似条件工作面出水的实例,最终预计工作面底板将出现小型涌水,工作面实际涌水量符合预计结果。     

企业如何选择存货的计价方法

存货在大多数企业资产总额中占有较大的比重，合理选择存货的计价方法对企业的经营成果有着重要的影响。选择不同的存货计价方法将会导致不同的成本水平、报告利润，并且对企业的税收负担，现金流量产生较大的影响。