21 research outputs found
Ram pressure and dusty red galaxies - key factors in the evolution of the multiple cluster system Abell 901/902
We present spectroscopic observations of 182 disk galaxies (96 in the cluster
and 86 in the field environment) in the region of the Abell 901/902 multiple
cluster system, which is located at a redshift of . The presence
of substructures and non-Gaussian redshift distributions indicate that the
cluster system is dynamically young and not in a virialized state. We find
evidence for two important galaxy populations. \textit{Morphologically
distorted galaxies} are probably subject to increased tidal interactions. They
show pronounced rotation curve asymmetries at intermediate cluster-centric
radii and low rest-frame peculiar velocities. \textit{Morphologically
undistorted galaxies} show the strongest rotation curve asymmetries at high
rest-frame velocities and low cluster-centric radii. Supposedly, this group is
strongly affected by ram-pressure stripping due to interaction with the
intra-cluster medium. Among the morphologically undistorted galaxies, dusty red
galaxies have particularly strong rotation curve asymmetries, suggesting ram
pressure is an important factor in these galaxies. Furthermore, dusty red
galaxies on average have a bulge-to-total ratio higher by a factor of two than
cluster blue cloud and field galaxies. The fraction of kinematically distorted
galaxies is 75% higher in the cluster than in the field environment. This
difference mainly stems from morphological undistorted galaxies, indicating a
cluster-specific interaction process that only affects the gas kinematics but
not the stellar morphology. Also the ratio between gas and stellar scale length
is reduced for cluster galaxies compared to the field sample. Both findings
could be best explained by ram-pressure effects.Comment: Electronic version published in Astronomy and Astrophysics Volume
549, Page 0; 19 pages, 21 figure
Tully-Fisher analysis of the multiple cluster system Abell 901/902
We derive rotation curves from optical emission lines of 182 disk galaxies
(96 in the cluster and 86 in the field) in the region of Abell 901/902 located
at . We focus on the analysis of B-band and stellar-mass
Tully-Fisher relations. We examine possible environmental dependencies and
differences between normal spirals and "dusty red" galaxies, i.e. disk galaxies
that have red colors due to relatively low star formation rates. We find no
significant differences between the best-fit TF slope of cluster and field
galaxies. At fixed slope, the field population with high-quality rotation
curves (57 objects) is brighter by \Delta M_{B}=-0\fm42\pm0\fm15 than the
cluster population (55 objects). We show that this slight difference is at
least in part an environmental effect. The scatter of the cluster TFR increases
for galaxies closer to the core region, also indicating an environmental
effect. Interestingly, dusty red galaxies become fainter towards the core at
given rotation velocity (i.e. total mass). This indicates that the star
formation in these galaxies is in the process of being quenched. The
luminosities of normal spiral galaxies are slightly higher at fixed rotation
velocity for smaller cluster-centric radii. Probably these galaxies are
gas-rich (compared to the dusty red population) and the onset of ram-pressure
stripping increases their star-formation rates. The results from the TF
analysis are consistent with and complement our previous findings. Dusty red
galaxies might be an intermediate stage in the transformation of infalling
field spiral galaxies into cluster S0s, and this might explain the well-known
increase of the S0 fraction in galaxy clusters with cosmic time.Comment: Accepted for publication in Astronomy and Astrophysics; 16 pages, 14
figure
Sustainable protected areas: Synergies between biodiversity conservation and socioeconomic development
1. Reconciling conservation and socioeconomic development goals is key to sus-
tainability but remains a source of fierce debate. Protected areas (PAs) are be-
lieved to play an essential role in achieving these seemingly conflicting goals.
Yet, there is limited evidence as to whether PAs are actually achieving the two
goals simultaneously.
2. Here, we investigate when and to what extent synergies or trade- offs between
biodiversity conservation and local socioeconomic development occur. To ex-
plore these relationships, we collected data across a wide range of socioeco-
nomic settings through face-to-face survey with PA managers from 114 African
and European PAs using structured questionnaire.
3. We found synergies between biodiversity conservation and socioeconomic
development for 62% of the PAs, albeit with significant differences between
African (55%) and European PAs (75%). Moreover, the sustainability of PAs in
conserving biodiversity was strongly correlated with the empowerment of the
PA management and the involvement of local communities in PA planning and
decision-making processes.
4. Our results demonstrate that for PAs to promote synergies between biodiver-
sity conservation and local socioeconomic development, and to enhance their
long-term sustainability, they should invest in the empowerment of their respec-
tive management and involvement of local communities in their planning and
management activitie
Sustainable protected areas: Synergies between biodiversity conservation and socioeconomic development
1. Reconciling conservation and socioeconomic development goals is key to sustainability but remains a source of fierce debate. Protected areas (PAs) are believed to play an essential role in achieving these seemingly conflicting goals. Yet, there is limited evidence as to whether PAs are actually achieving the two goals simultaneously. 2. Here, we investigate when and to what extent synergies or trade‐offs between biodiversity conservation and local socioeconomic development occur. To explore these relationships, we collected data across a wide range of socioeconomic settings through face‐to‐face survey with PA managers from 114 African and European PAs using structured questionnaire. 3. We found synergies between biodiversity conservation and socioeconomic development for 62% of the PAs, albeit with significant differences between African (55%) and European PAs (75%). Moreover, the sustainability of PAs in conserving biodiversity was strongly correlated with the empowerment of the PA management and the involvement of local communities in PA planning and decision‐making processes. 4. Our results demonstrate that for PAs to promote synergies between biodiversity conservation and local socioeconomic development, and to enhance their long‐term sustainability, they should invest in the empowerment of their respective management and involvement of local communities in their planning and management activities
Analysis of differences and commonalities in wildlife hunting across the Africa-Europe South-North gradient
Hunting and its impacts on wildlife are typically studied regionally, with a particular focus on the Global South. Hunting can, however, also undermine rewilding efforts or threaten wildlife in the Global North. Little is known about how hunting manifests under varying socioeconomic and ecological contexts across the Global South and North. Herein, we examined differences and commonalities in hunting characteristics across an exemplary Global South-North gradient approximated by the Human Development Index (HDI) using face-to-face interviews with 114 protected area (PA) managers in 25 African and European countries. Generally, we observed that hunting ranges from the illegal, economically motivated, and unsustainable hunting of herbivores in the South to the legal, socially and ecologically motivated hunting of ungulates within parks and the illegal hunting of mainly predators outside parks in the North. Commonalities across this Africa-Europe South-North gradient included increased conflict-related killings in human-dominated landscapes and decreased illegal hunting with beneficial community conditions, such as mutual trust resulting from community involvement in PA management. Nevertheless, local conditions cannot outweigh the strong effect of the HDI on unsustainable hunting. Our findings highlight regional challenges that require collaborative, integrative efforts in wildlife conservation across actors, while identified commonalities may outline universal mechanisms for achieving this goal.publishedVersio
Os Acromiale in Reverse Total Shoulder Arthroplasty: A Cohort Study
Background
Increased passive deltoid tension after reverse total shoulder arthroplasty (RTSA) potentially leads to displacement or tilting of a preexisting os acromiale.
Purpose
To analyze patients with an os acromiale who underwent RTSA and compare their outcomes and complications with a matched control group without an os acromiale.
Study Design
Cohort study; Level of evidence, 3.
Methods
In this study, 45 shoulders in 42 patients with an os acromiale (cases) were matched to 133 patients without os acromiale (controls) who underwent RTSA between 2005 and 2016. The mean follow-up was 52 ± 32 months. Matching criteria included sex, type of surgery, duration of follow-up, and age. The Constant score (CS), Subjective Shoulder Value (SSV), and radiological outcomes were assessed postoperatively at 1-year, 2-year, and final follow-up visits.
Results
The mean CS, SSV, and range of motion improved from preoperative levels to the final follow-up in both groups (P < .01). Patients with an os acromiale had a relative CS of 70 ± 23 versus 76 ± 21 points (P = .15) and an SSV of 70 ± 30 versus 73 ± 24 (P = .52) compared with controls at the final follow-up visit. Patients with an os acromiale had significantly decreased active flexion of 104° ± 33° versus 114° ± 33° (P = .03) at 1 year and active abduction of 103° ± 37° versus 121° ± 38° at 2 years postoperatively (P = .02). A postoperatively painful os acromiale was found in 12 cases (27%) and spontaneously resolved in 8 cases after a mean of 33 months (range, 12-47 months; P = .04).
Conclusion
RTSA reliably restores patient satisfaction despite the presence of an os acromiale, with a slightly impaired range of motion. Postoperative local tenderness at the os acromiale can be expected in 1 out of 4 patients, but this resolves spontaneously over time in the majority of patients
Retrieval of aerosol optical depth over the Arctic cryosphere during spring and summer using satellite observations
The climate in the Arctic has warmed much more quickly in the last 2 to 3 decades than at the mid-latitudes, i.e., during the Arctic amplification (AA) period. Radiative forcing in the Arctic is influenced both directly and indirectly by aerosols. However, their observation from ground or airborne instruments is challenging, and thus measurements are sparse. In this study, total aerosol optical depth (AOD) is determined from top-of-atmosphere reflectance measurements by the Advanced Along-Track Scanning Radiometer (AATSR) on board ENVISAT over snow and ice in the Arctic using a retrieval called AEROSNOW for the period 2003 to 2011. AEROSNOW incorporates an existing aerosol retrieval algorithm with a cloud-masking algorithm, alongside a novel quality-flagging methodology specifically designed for implementation in the high Arctic region (≥ 72 N). We use the dual-viewing capability of the AATSR instrument to accurately determine the contribution of aerosol to the reflection at the top of the atmosphere for observations over the bright surfaces of the cryosphere in the Arctic. The AOD is retrieved assuming that the surface reflectance observed by the satellite can be well parameterized by a bidirectional snow reflectance distribution function (BRDF). The spatial distribution of AOD shows that high values in spring (March, April, May) and lower values in summer (June, July, August) are observed. The AEROSNOW AOD values are consistent with those from collocated Aerosol Robotic Network (AERONET) measurements, with no systematic bias found as a function of time. The AEROSNOW AOD in the high Arctic was validated by comparison with ground-based measurements at the PEARL, OPAL, Hornsund, and Thule stations. The AEROSNOW AOD value is less than 0.15 on average, and the linear regression of AEROSNOW and AERONET total AOD yields a slope of 0.98, a Pearson correlation coefficient of R=0.86, and a root mean square error (RMSE) of =0.01 for the monthly scale in both spring and summer. The AEROSNOW observation of increased AOD values over the high Arctic cryosphere during spring confirms clearly that Arctic haze events were well captured by this dataset. In addition, the AEROSNOW AOD results provide a novel and unique total AOD data product for the springtime and summertime from 2003 to 2011. These AOD values, retrieved from spaceborne observation, provide a unique insight into the high Arctic cryospheric region at high spatial resolution and temporal coverage
Sustainable protected areas: Synergies between biodiversity conservation and socioeconomic development
1. Reconciling conservation and socioeconomic development goals is key to sus-
tainability but remains a source of fierce debate. Protected areas (PAs) are be-
lieved to play an essential role in achieving these seemingly conflicting goals.
Yet, there is limited evidence as to whether PAs are actually achieving the two
goals simultaneously.
2. Here, we investigate when and to what extent synergies or trade- offs between
biodiversity conservation and local socioeconomic development occur. To ex-
plore these relationships, we collected data across a wide range of socioeco-
nomic settings through face-to-face survey with PA managers from 114 African
and European PAs using structured questionnaire.
3. We found synergies between biodiversity conservation and socioeconomic
development for 62% of the PAs, albeit with significant differences between
African (55%) and European PAs (75%). Moreover, the sustainability of PAs in
conserving biodiversity was strongly correlated with the empowerment of the
PA management and the involvement of local communities in PA planning and
decision-making processes.
4. Our results demonstrate that for PAs to promote synergies between biodiver-
sity conservation and local socioeconomic development, and to enhance their
long-term sustainability, they should invest in the empowerment of their respec-
tive management and involvement of local communities in their planning and
management activitie
Sustainable protected areas: Synergies between biodiversity conservation and socioeconomic development
1. Reconciling conservation and socioeconomic development goals is key to sus-
tainability but remains a source of fierce debate. Protected areas (PAs) are be-
lieved to play an essential role in achieving these seemingly conflicting goals.
Yet, there is limited evidence as to whether PAs are actually achieving the two
goals simultaneously.
2. Here, we investigate when and to what extent synergies or trade- offs between
biodiversity conservation and local socioeconomic development occur. To ex-
plore these relationships, we collected data across a wide range of socioeco-
nomic settings through face-to-face survey with PA managers from 114 African
and European PAs using structured questionnaire.
3. We found synergies between biodiversity conservation and socioeconomic
development for 62% of the PAs, albeit with significant differences between
African (55%) and European PAs (75%). Moreover, the sustainability of PAs in
conserving biodiversity was strongly correlated with the empowerment of the
PA management and the involvement of local communities in PA planning and
decision-making processes.
4. Our results demonstrate that for PAs to promote synergies between biodiver-
sity conservation and local socioeconomic development, and to enhance their
long-term sustainability, they should invest in the empowerment of their respec-
tive management and involvement of local communities in their planning and
management activitie