The global decline of terrestrial species is largely due to the degradation, loss and fragmentation of their habitats. The conversion of natural ecosystems for cropland, rangeland, forest products ...and human infrastructure are the primary causes of habitat deterioration. Due to the paucity of data on the past distribution of species and the scarcity of fine‐scale habitat conversion maps, however, accurate assessment of the recent effects of habitat degradation, loss and fragmentation on the range of mammals has been near impossible. We aim to assess the proportions of available habitat within the lost and retained parts of mammals' distribution ranges, and to identify the drivers of habitat availability. We produced distribution maps for 475 terrestrial mammals for the range they occupied 50 years ago and compared them to current range maps. We then calculated the differences in the percentage of ‘area of habitat’ (habitat available to a species within its range) between the lost and retained range areas. Finally, we ran generalized linear mixed models to identify which variables were more influential in determining habitat availability in the lost and retained parts of the distribution ranges. We found that 59% of species had a lower proportion of available habitat in the lost range compared to the retained range, thus hypothesizing that habitat loss could have contributed to range declines. The most important factors negatively affecting habitat availability were the conversion of land to rangeland and high density of livestock. Significant intrinsic traits were those related to reproductive timing and output, habitat breadth and medium body size. Our findings emphasize the importance of implementing conservation strategies to mitigate the impacts caused by human activities on the habitats of mammals, and offer evidence indicating which species have the potential to reoccupy portions of their former range if other threats cease to occur.
This study investigates the impact of habitat degradation on terrestrial mammal species. By comparing historic and current distribution maps for 475 species, we found that 59% of them have less available habitat in their lost ranges, suggesting habitat loss contributed to range declines. Factors like land conversion to rangeland and high livestock density negatively affected habitat availability. Intrinsic traits such as reproductive timing, habitat breadth and medium body size also played a role. The study underscores the need for conservation efforts to mitigate human‐induced habitat threats and identifies species that could potentially reclaim lost range if threats are addressed.
Transcatheter therapies are emerging for functional mitral regurgitation (FMR) treatment, however there is lack of pathological models for their preclinical assessment. We investigated the ...applicability of deer hearts for this purpose.
8 whole deer hearts were housed in a pulsatile flow bench. At baseline, all mitral valves featured normal coaptation. The pathological state was induced by 60-minutes intraventricular constant pressurization. It caused mitral annulus dilation (antero-posterior diameter increase from 31.8 ± 5.6 mm to 39.5 ± 4.9 mm, p = 0.001), leaflets tethering (maximal tenting height increase from 7.3 ± 2.5 mm to 12.7 ± 3.4 mm, p < 0.001) and left ventricular diameter increase (from 67.8 ± 7.5 mm to 79.4 ± 6.5 mm, p = 0.004). These geometrical reconfigurations led to restricted mitral valve leaflets motion and leaflet coaptation loss. Preliminary feasibility assessment of two FMR treatments was performed in the developed model.
Deer hearts showed ability to dilate under constant pressurization and have potential to be used for realistic preclinical research of novel FMR therapies.
Graphical abstract figure legend: Deer heart mitral valve fiberscopic and echocardiographic images in peak systole at baseline and after inducing the pathological conditions representing functional mitral regurgitation. In the pathological conditions lack of coaptation between the leaflets, enlargement of the antero-posterior distance (red dashed line) and the left ventricular diameter (orange dashed line) were observed.
Abstract Objectives Customized chemotherapy has several advantages: patients are more likely to be treated with the most effective agents and can be spared the toxicity of ineffective drugs. Based on ...the literature, excision repair cross complementation group 1 (ERCC1) and ribonucleotide reductase M1 (RRM1) genes represent predictive biomarkers of response to platinum compound and gemcitabine, in NSCLC. Materials and methods We had planned a phase II trial (Simon design) to evaluate combination chemotherapy according to single nucleotide polymorphisms (SNPs) of ERCC1 (118T/C and 8092C/A) and RRM1 (−37C/A and −524T/C) in naïve patients affected by advanced NSCLC. ERCC1 and RRM1 SNPs assessment was performed in peripheral blood lymphocytes (PBLs). Combination chemotherapy was selected based on ERCC1 and RRM1 SNPs: we assume that patients with one or two C alleles at position 118 and with one or two A alleles at position 8092 in ERCC1 gene would correspond to Cisplatin non-responder and than with two A alleles at −37 and two C alleles at −524 in RRM1 gene to gemcitabine non-responder. Four schedules were provided: cisplatin + gemcitabine, cisplatin + docetaxel, gemcitabine + docetaxel; docetaxel + vinorelbine. Primary endpoint was overall response (ORR) in the intention-to-treat population. Results 42 patients were enrolled from January 2010 to November 2011; 40 patients received at least 1 cycle of chemotherapy; median age was 66 years (range: 47–72); 36(90%) had stage IV, 4(10%) IIIB; 23(58%) had adenocarcinoma, 14(35%) squamous carcinoma. Twenty-five (62%) patients received treatment A, 3(8%) treatment B, 11(28%) treatment C, 1(23%) treatment D. ORR was 55%, analysis in squamous patients subgroups showed 71.4% ORR. The median follow-up was 19.7 months, PFS was 23 weeks (95% CI = 15–26) and OS was 40.4 weeks (95% CI = 32–55). Treatment was well tolerated. Conclusion We observed an increase of ORR in NSCLC patients when they were treated with chemotherapy according to ERCC1 and RRM1 SNPs status.
Several novel approaches were recently developed to treat aortic root pathologies. The alteration induced by some of these approaches to the biomechanics of the aortic root could possibly affect the ...coronary perfusion, compromising the procedural outcome. In this scenario, the need to replicate in vitro the coronary flow pattern in physiological and pathological conditions is becoming crucial for the functional assessment of novel devices and techniques. This article describes the design of an easy-to-use, left-and-right coronary impedance simulator, coupled with native aortic roots for in vitro pulsatile tests. Experiments were performed in order to assess the performances of the coronary impedance simulator when coupled with healthy aortic valves (cardiac output: 3.8 ± 0.26 l min
; mean systemic pressure: 95 ± 1.3 mmHg; mean coronary flow rate: 272 ± 13.4 ml min
) or with regurgitant valves (cardiac output: 1.9 ± 0.24 l min
; mean systemic pressure of 45 ± 3.3 mmHg; mean coronary flow rate:149 ± 21.9 ml min
). The acute systemic response to valve regurgitation was also replicated, with increased beat rate and afterload, aimed at restoring the systemic pressure (cardiac output: 2.5 ± 0.23 l min
; mean systemic pressure of 109 ± 6.1 mmHg; mean coronary flow rate: 262 ± 35.5 ml min
). In the test conditions, the system was able to replicate in vitro the main determinants of the coronary circulation with physiological left/right coronary flow rate repartition, and a realistic interaction between coronary and systemic hemodynamics. The coronary simulator appears to be a suitable platform to study and optimize the interactions between novel approaches to aortic valve pathology and the coronary perfusion.
The presence of exotic states of matter in neutron stars (NSs) is currently an open issue in physics. The appearance of muons, kaons, hyperons, and other exotic particles in the inner regions of the ...NS, favoured by energetic considerations, is considered to be an effective mechanism to soften the equation of state (EoS). In the so-called
two-families scenario
, the softening of the EoS allows for NSs characterized by very small radii, which become unstable and convert into a quark stars (QSs). In the process of conversion of a NS into a QS material can be ablated by neutrinos from the surface of the star. Not only neutron-rich nuclei, but also more exotic material, such as hypernuclei or deconfined quarks, could be ejected into the atmosphere. In the NS atmosphere, atoms like H, He, and C should exist, and attempts to model the NS thermal emission taking into account their presence, with spectra modified by the extreme magnetic fields, have been done. However, exotic atoms, like muonic hydrogen (
p
μ
−
) or the so-called
Sigmium
(Σ
+
e
−
), could also be present during the conversion process or in its immediate aftermath. At present, analytical expressions of the wave functions and eigenvalues for these atoms have been calculated only for H. In this work, we extend the existing solutions and parametrizations to the exotic atoms (
p μ
−
) and (Σ
+
e
−
), making some predictions on possible transitions. Their detection in the spectra of NS would provide experimental evidence for the existence of hyperons in the interior of these stars.
KAIUM at DAΦNE? Lucherini, Vincenzo; Bressani, Tullio; Fontana, Andrea
Hyperfine interactions,
09/2009, Volume:
193, Issue:
1-3
Journal Article
Peer reviewed
Open access
The possibility of producing and detecting at DA
Φ
NE a new hydrogen
isotope
formed by a (
K
+
e
−
) bound system (
Kaium
) is addressed, considering a dedicated, and relatively simple experiment ...of short duration. If Kaium will be detected, it could in perspective pave the way for a series of highly sophisticated experiments focused on the precision measurement of several observables, as the
K
+
−
K
−
mass difference, strictly related to CPT invariance.
The presence of exotic states of matter in neutron stars (NSs) is currently an open issue in physics. The appearance of muons, kaons, hyperons, and other exotic particles in the inner regions of the ...NS, favored by energetic considerations, is considered to be an effective mechanism to soften the equation of state (EoS). In the so-called two-families scenario, the softening of the EoS allows for NSs characterized by very small radii, which become unstable and convert into a quark stars (QSs). In the process of conversion of a NS into a QS material can be ablated by neutrinos from the surface of the star. Not only neutron-rich nuclei, but also more exotic material, such as hypernuclei or deconfined quarks, could be ejected into the atmosphere. In the NS atmosphere, atoms like H, He, and C should exist, and attempts to model the NS thermal emission taking into account their presence, with spectra modified by the extreme magnetic fields, have been done. However, exotic atoms, like muonic hydrogen \((p\,\mu^-)\) or the so-called Sigmium \((\Sigma^+\,e^-)\), could also be present during the conversion process or in its immediate aftermath. At present, analytical expressions of the wave functions and eigenvalues for these atoms have been calculated only for H. In this work, we extend the existing solutions and parametrizations to the exotic atoms \((p\,\mu^-)\) and \((\Sigma^+\,e^-)\), making some predictions on possible transitions. Their detection in the spectra of NS would provide experimental evidence for the existence of hyperons in the interior of these stars.
L'istrice, il più grande roditore della fauna italiana, ha colonizzato negli ultimi 30 anni gran parte del territorio italiano, ma ancora scarse sono le conoscenze scientifiche su questa specie. ...L'istrice, un erbivoro generalista capace di colonizzare habitat molto diversi, mostra una marcata flessibilità nell´uso dello spazio: lo home range può variare da poco più di 10 ha a oltre 700 ha e i siti di alimentazione visitati possono essere localizzati a oltre 4 km dalla tana. Lo studio dell'uso dello habitat di questa specie in ambienti diversi è pertanto un problema scientifico particolarmente interessante. Tra gennaio 1994 e giugno 1995 sono stati monitorati tramite telemetria 6 individui adulti in un'area prevalentemente rurale alla periferia di Siena, mentre tra agosto 1998 e settembre 2001 sono stati monitorati 10 individui adulti nel Parco Regionale della Maremma, un'area costiera mediterranea. L'uso dello habitat è stato studiato al secondo e al terzo livello di selezione, cioè composizione in habitat degli home range e selezione dello habitat all'interno degli home range . Bosco, macchia, prati e pascoli predominavano negli home range individuali, al contrario di coltivi, zone edificate, zone umide e zone dunali. All'interno degli home range in entrambe le aree di studio, nonostante marcate variazioni individuali nell'uso e selezione dello habitat, i coltivi sono stati sotto-utilizzati, mentre boschi, macchia, prati e pascoli sono stati selezionati positivamente o usati secondo la loro disponibilità. Inoltre, la pineta e la zona di spiaggia e duna, presenti solo nel Parco della Maremma, sono stati selezionati negativamente mentre siepi e fossi, presenti solo a Siena, sono stati selezionati positivamente. Questi risultati costituiscono una base di partenza per la gestione di questa specie.
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