Decomposing Colour Structures into Multiplet Bases

In this thesis a method for decomposing QCD colour structures into multiplet bases is described. The method is applicable for any number of gluons and quarks. To achieve the decomposition requires the knowledge of group theoretical weights, so-called Wigner 3j and 6j coefficients. The number of required coefficients have been calculated for up to 12 external gluons, and been shown to scale well in the number of external partons. How to calculate the coefficients have been shown and for 6 external gluons they have been calculated. Furthermore the colour structures of Ng-1 basis vectors radiating a gluon have been decomposed into the Ng basis vectors. The viability of this has been examined for up to 10 external gluons by counting how many Ng basis vectors are projected on by the colour structures

Cerebral oedema after reperfusion therapy in patients with ischaemic stroke : predictors, outcomes and treatment

Introduction: Reperfusion therapy by intravenous thrombolysis (IVT) and/or endovascular thrombectomy (EVT) are established treatments in ischaemic stroke. Cerebral oedema (COED), caused by dysfunction the blood brain barrier (BBB), is common early after acute ischaemic stroke (AIS), can aggravate the symptoms and worsen the prognosis. Data on predictors and the effect of recanalization on early COED is limited. A large infarction with COED involving the middle cerebral artery (MCA) can be life-threatening. Decompressive hemicraniectomy (DHC) reduces mortality and may have a positive effect on functional outcome in younger patients. Animal data suggest that imatinib, a tyrosine kinase inhibitor, may restore BBB integrity, thereby reducing haemorrhagic transformation (HT) and COED. The aim of this doctoral thesis was to contribute to the understanding of clinical aspects of COED in patients with AIS of the anterior circulation. Methods: Paper I, II and IV reported retrospective, observational studies using data from the Safe Implementations of Treatments in Stroke (SITS) International Stroke Registry, a prospective, multinational registry. These studies included patient data recorded using the SITS Registry data collection protocols for IVT and EVT, and to some extent general stroke, in time periods between 2002 and 2019. All patients had presumed ischaemic stroke. Paper III reported a phase 2, randomized, open-label, pilot study of imatinib in patients who received IVT after ischaemic stroke at 5 hospitals in Stockholm 2011-2014. All papers evaluated COED using the SITS COED scale (no, mild, moderate or severe COED). Outcomes at 3 months were functional outcome using the modified Rankin scale (mRS) score and death of any cause. Results: In paper I, the most important predictors of COED after AIS were assessed. Among 42 187 patients (median age 70 years), 12.5% had mild COED on follow-up imaging (22-36 hours or any extra investigation) and 10.2% had moderate or severe COED. Baseline National Institutes of Health Stroke Scale (NIHSS) score, followed by hyperdense artery sign (HAS), were the strongest predictors for COED. Additionally, higher blood glucose, impaired level of consciousness and imaging signs of early infarction at baseline were predictors for COED. Increasing degree of COED at 22-36 hours was associated with increasing mortality and worse functional outcome at 3 months. In paper II, the effect of recanalization on COED was assessed. Reperfusion therapy was administered to the 22 184 patients (median age 71 years and NIHSS score 16): only IVT (82.6%), IVT and EVT (13.8%) or only EVT (3.6%). Overall, recanalization was associated with a 10.6% (p<0.001) absolute risk reduction of moderate to severe COED at 22-36 hours, relative risk (RR) 0.55 (95% CI 0.52-0.58). Two models with high predictive ability provided the following estimates: adjusted OR 0.52 (95% CI, 0.46-0.59) and, with additional adjustment for parenchymal haemorrhage (PH), OR 0.46 (95% CI, 0.41-0.52). Moreover, recanalization was associated with a 13.6% (p<0.001) absolute reduction of mortality at 3 months, RR 0.58 (95% CI 0.55-0.61), adjusted OR 0.48 (95% CI 0.45-0.53). In paper III, 60 patients were randomized (15 patients in low-dose, 14 patients in medium and high-dose and 17 patients in control). Four serious adverse events (2 in control and 2 in low-dose group) resulted in the death of 3 patients. Of the dead patients 2 were allocated to low-dose group but of these, 1 did not receive imatinib and 1 patient had received only 2 doses. In the per protocol analysis, there were 21 haemorrhagic infarctions (6 in control), 3 PH (1 in control) and 4 remote parenchymal haemorrhages (0 in control). There were 33 cases of COED with moderate to severe COED being less frequent with higher doses, and no cases of moderate to severe COED in the high-dose group. After adjustment for EVT, the mean improvement in the NIHSS score compared to controls was 2 points (p=0.259) for the low-dose group, 3 points (p=0.106) for the medium-dose groups and 5 points (p=0.012) for the high-dose group. Functional independence (mRS 0-2) at 3 months was observed in 61% of the control group and 72% of all imatinib-treated patients; OR, adjusted for EVT, was 2.33 (95% CI 0.48-11.44). Paper IV reported anterior circulation AIS patients that underwent DHC. In 684 patients from 35 countries median age was 56 years and NIHSS score at baseline 18 and 98.1% received reperfusion therapy. Moderate to severe COED was detected in in 76.0% and PH in 25.8% at 22-36 hours follow-up imaging scans. Surgery-related details, for example timing of DHC, were not registered. Mortality at 3 months was 32.7% (159/486). Among baseline variables, only increasing age was independently associated with death (OR 1.06, 95% CI 1.03-1.08). Good outcome (mRS 0-3) at 3 months was observed in 13.9% (66/475) and mRS 0-4 was observed in 39.4% (187/475). Outcomes differed between patients aged ≤60 years ≥61 years (25.2% versus 47.8% for mortality and 16.6% versus 8.4% for good outcome). Right-sided involvement of vascular territory was more common than left-sided. Conclusions: The most important baseline predictors for early COED are NIHSS score, HAS, higher blood glucose, decreased level of consciousness, and signs of acute infarction at baseline. This finding can be used to improve selection and monitoring of patients for drug or surgical treatment. In patients with AIS, recanalization was associated with a lower risk for early COED even after adjustment for higher rate of PH in recanalized patients. Imatinib is safe and tolerable and may reduce neurological disability in patients treated with IVT after AIS. A confirmatory randomized trial is ongoing. DHC in routine clinical practice may have worse outcomes than randomized trials, although there are caveats due to short follow-up of the patients in this study. Right-sided arterial occlusions were more common than left-sided, which indicates a tendency to perform DHC in infarctions of the right hemisphere. In general, this doctoral thesis added new knowledge about several aspects of COED in AIS and a potential new pharmacological therapy for acute ischaemic stroke. Further research is required to confirm these results which are based on 3 retrospective observational studies and one phase 2 pilot study. In fact, an efficacy trial of imatinib is now ongoing

“Problem or Resource?” - An anthropological journey through, and with, oil -

This thesis explores narratives in and around the Norwegian oil industry, with a particular focus on the industrial park in Mongstad and based on multi-sited methods, brief ethnographic fieldwork stints as well as digital correspondence. More specifically, the thesis examines how the establishment of the industrial park has affected and changed the lives and livelihoods, neighborhoods and local environments in Mongstad, including the ways in which narratives of oil as Progress are being re-negotiated in the context of climate crisis. The thesis pays particular attention to discussions of the materiality and fundamental “leakiness” of oil to address subjects concerning an imagined future, environmentalism, and capitalism. Because of the modest amount of ethnographic data collected during the short stints of fieldwork the author decided to include autoethnographic accounts to tie it all together.Master's ThesisSANT350MASV-SAN

Prediction and monitoring of in-hospital cardiac arrest

Background: In-hospital cardiac arrest (IHCA) is a global health concern of major importance, associated with a poor prognosis. IHCA is frequently heralded by a deterioration of vital signs, and many cases are considered preventable. Hence, prevention has become a key strategy. The overall aim of this thesis was to study the prevention of IHCA, by means of prediction and monitoring, with a view to improve patient safety. Methods: Study I and III are observational cohort studies, based on the Swedish Registry of Cardiopulmonary Resuscitation (SRCR). In study III, we also collected additional data from medical records in a small, hypothesis-generating group of patients. Study II and IV are prospective, observational cohort studies based on patients reviewed by Rapid Response Teams (RRTs) in 26 and 24 Swedish hospitals, respectively. In study IV, additional data on long-term survival was obtained from either medical records or the personal information directory, containing population registration data. Specific study aims and results: In study I, we investigated how 30-day survival after IHCA was influenced by ECG monitoring at the time of collapse, as well as clinical factors that determined whether patients were ECG monitored adjacent to cardiac arrest (CA). In all, 24,790 patients were enrolled in the SRCR between 2008 and 2017. After applying the exclusion criteria, 19,225 patients remained, of which 52% were monitored at the time of collapse. In all, 30-day survival was 30%. ECG monitoring at the time of CA was associated with a Hazard Ratio of 0.62 (95% Confidence Interval 0.60-0.64) for 30-day mortality. The strongest predictor of ECG monitoring adjacent to IHCA was location in hospital. There were tangible variations in the frequency of patients who were ECG monitored at the time of collapse between Swedish regions and across hospitals. In study II, we investigated the predictive power of NEWS 2, as compared to NEWS, in identifying patients at risk of Serious Adverse Events (SAEs) within 24 hours of an RRT-review. In all, 1,065 patients, reviewed by RRTs in general wards during the study period between October 2019 and January 2020, were included. After applying the exclusion criteria, 898 patients were eligible for complete case analyses. In all, 37% of the patients were admitted to the Intensive care unit (ICU) within 24 hours of RRT-review. In-hospital mortality and IHCA were uncommon (6% and 1% respectively). The Area Under the Receiver Operating Characteristic (AUROC) for both NEWS and NEWS 2 was 0.62 for the composite outcome, and 0.69/0.67 for mortality. Regarding the outcome unanticipated ICU admission, the AUROC was 0.59 and 0.60, respectively, while the AUROC for IHCA was 0.51 (NEWS) and 0.47 (NEWS 2), respectively. In study III, we investigated 30-day survival and ROSC in patients suffering from IHCA, who were reviewed by an RRT within 24 hours prior to the CA, as compared to those without such review. Furthermore, we studied patient centred factors prior to RRT activation, the timeliness of the RRT-review as well as the reason for the RRT-review. We also investigated the association between RRT interventions and outcome. During the study period between 2014 and 2021, 19,973 patents were enrolled in the SRCR. After applying the exclusion criteria, 12,915 patients remained. Among these IHCA patients, there was an RRT/ICU contact within 24 hours prior to the CA in 2,058 cases (19%). The adjusted 30-day survival was lower among patients reviewed by an RRT prior to IHCA (25% vs. 33%, p <0.001). Regarding ROSC, we did not observe any difference between the groups. The propensity score based Odds Ratio for 30- day survival was 0.92 for patients who were reviewed by an RRT (95% CI 0.90 to 0.94, p <0.001), as compared to those who were not RRT- reviewed within 24 hours prior to IHCA. A respiratory cause of CA was more common among IHCA patients who were reviewed by an RRT. In the small, explorative subgroup (n=82), 24% of the RRT activations were delayed, and respiratory distress was the most common RRT trigger. We observed a significantly lower 30-day survival among patients triaged to remain at ward compared to those triaged to a higher level of care (2% vs. 20%, p 0.016). In study IV, we explored the impact of age on the ability of NEWS 2 to predict IHCA, unanticipated ICU-admission, or death, and the composite of these three SAEs, within 24 hours of review by an RRT. Furthermore, we aimed to investigate 30-, 90- and 180-day mortality, and the discriminative ability of NEWS 2 in the prediction of long-term mortality among RRT-reviewed patients. In this multi-centre study based on data prospectively collected by RRTs, the NEWS 2 scores of all patients were retrospectively, digitally calculated by the study team. Age was analysed as a continuous variable, in a spline regression model, and categorized into five different models, subsequently explored as additive variables to NEWS 2. The discriminative ability of NEWS 2 in predicting 30-day mortality improved by adding age as a covariate (from AUROC 0.66, 0.62-0.70 to 0.70, 0.65-0.73, p=0.01). There were differences across age groups, with the best predictive performance identified among patients aged 45-54 years. The 30-, 90-and 180-day mortality was 31%, 33%, and 36%, respectively. Conclusion: ECG monitoring at the time of IHCA was associated with a 38% reduction of adjusted mortality. Despite this finding, only one in two IHCA patients were ECG monitored. The most important factor influencing ECG monitoring was which type of hospital ward the patient was admitted to. The tangible variations in the frequency of ECG monitoring adjacent to IHCA observed between Swedish regions and across hospitals need to be investigated in future studies. Guidelines for the monitoring of patients at risk of CA could contribute to an improved outcome. The prognostic accuracy of NEWS 2 in predicting mortality within 24 hours of an RRT-review was acceptable, whereas the discriminative ability in prediction of unanticipated ICU-admission and the composite outcome was rather weak. Regarding the prediction of IHCA, NEWS 2 performed poorly. There was no difference in the prognostic accuracy between NEWS and NEWS 2; however, the discriminative ability was not considered sufficient to serve as a triage tool in RRT-reviewed patients. In-hospital cardiac arrest among patients who were reviewed by an RRT prior to CA was associated with a poorer prognosis, and a more frequent respiratory aetiology of the CA. In the explorative sub-group of patients, RRT activation was frequently delayed, the most common trigger for RRT-review was respiratory distress, and escalation of the level of care was associated with an improved prognosis. Early identification of patients with abnormal respiratory vital signs, followed by a timely response, may have a potential to improve the prognosis for patients reviewed by an RRT and prevent IHCA. Adding age as a covariate improved the discriminative ability of NEWS 2 in the prediction of 30-day mortality among RRT-reviewed patients. The ability differed across age categories. Overall, the long-term prognosis of RRT-reviewed patients was poor. Our results indicate that age merits further validation as a covariate to improve the performance of NEWS 2

CYP2D6-polymorphism and effect of adjuvant tamoxifen in breast cancer patients

Adjuvant tamoxifen at the standard dose of 20 mg daily for five to ten years reduces the risk for relapse and mortality in hormone sensitive breast cancer. The effect however varies and no early marker of poor response is yet available. Varying activation of tamoxifen due to polymorphism in the CYP2D6 gene has been suggested to influence the effect of the treatment, but data are inconsistent. Our previous study in a smaller cohort of tamoxifen treated early breast cancer diagnosed 1998-2000 indicated a poorer prognosis in premenopausal patients with reduced CYP2D6 activity. The overall aim of this thesis was to investigate various aspects of tamoxifen treatment to facilitate improved personalized endocrine treatment strategies in early breast cancer, with individualized tamoxifen dosing, to improve quality of life, adherence and prognosis. In study I we investigated the correlation between CYP2D6 genotype and tamoxifen metabolite levels in plasma, focusing on reduced function CYP2D6 variants (n=118). We also explored the relationship between endoxifen levels and adverse effects to tamoxifen. The degree of side effects to tamoxifen appeared to be dependent on endoxifen concentration. We found a distinct correlation between CYP2D6 activity and plasma concentrations of endoxifen. The effect of reduced function variants, in particular CYP2D6*41, on endoxifen formation was greater than anticipated. Markedly reduced endoxifen concentrations were seen in all homozygous carriers of CYP2D6 no function variants and in those with two reduced activity alleles. The fraction of patients with poor tamoxifen activation might thus be larger than expected. This may be important information for future genotype-based tamoxifen dosing. Although the clinical relevance of the proposed target level of endoxifen at around 5.9 ng/mL needs to be evaluated, it is concerning that a third of our study patients had endoxifen concentrations below this level with tamoxifen at the current standard dose. This underlines the importance of further work to define a target concentration of endoxifen for clinical benefit. In study II we investigated the effect of CYP2D6 activity and other systemic adjuvant therapy on mammographic density (MD) change (n=699) in tamoxifen treated patients. As expected, MD declined during follow up, with a more prominent decrease in the premenopausal subgroup. Other systemic adjuvant treatment did not further extend density decline in this tamoxifen treated cohort. Density reduction appeared to persist after tamoxifen was stopped. Importantly, the previously proposed correlation between CYP2D6 activity and density change in patients with adjuvant tamoxifen could not be confirmed in this cohort with modern complex systemic adjuvant treatment. More data is needed to ascertain whether mammographic density change may be used as a marker of the desired effect of adjuvant tamoxifen. In study III we compared information from patient records to data from the National Prescribed Drug Register in Sweden on adherence to adjuvant endocrine treatment (n=1235). We also investigated the association between CYP2D6-activity, menopausal status, the patients’ risk for relapse and adherence. Consistency, i.e. agreement, between the two sources of adherence data was good, 86%, when including medication with an aromatase inhibitor (AI) after tamoxifen. In those with at least 4.5 years follow up, adherence to adjuvant tamoxifen was reasonable, 72% and increased to 82%, when including subsequent AIs, based on prescription refill data. Adherence was not found to vary by menopausal status or recurrence risk. Unexpectedly, adherence to tamoxifen was lower in CYP2D6 poor metabolizers, despite data proposing a reduced risk of adverse effects in this group. In study IV we aimed to validate our previous findings in a larger material in a more modern setting (n=1105), with tamoxifen treated patients operated between 2006-2014, who could also be subject to improved multimodal adjuvant therapy compared to the patients in our older study and to determine if the effect of CYP2D6 genotype is affected by menopausal status. Compared with our previous study, fewer patients, 12%, had a relapse and only 4% died from breast cancer under the 11-year follow-up. In summary, no obvious correlation between poor CYP2D6 activity and a worse prognosis was found in this material, accounting for adherence to tamoxifen and CYP2D6 inhibitors. A correlation between low CYP2D6 activity and a poorer prognosis in premenopausal tamoxifen treated early breast cancer was thus not confirmed. Breast cancer treatment has steadily improved over time. A possible negative effect of poor CYP2D6 activity on clinical outcome in tamoxifen treated patients is therefore likely marginal in a clinical setting with access to multimodal postoperative breast cancer treatment. Although our results do not support CYP2D6 testing for patients with adjuvant tamoxifen in a multimodal clinical setting, we cannot exclude that CYP2D6 genotyping might still be of value in selected groups, such as in in a low resource setting, where many patients, including those at higher risk of relapse, receive tamoxifen monotherapy. Therapeutic drug monitoring of tamoxifen to secure sufficient plasma levels of endoxifen for clinical efficacy and to avoid excess drug exposure associated with severe side effects might also be relevant in the future. In conclusion, this thesis contributes to the knowledge on CYP2D6 polymorphism and the effect of postoperative tamoxifen in a multimodal setting, the correlation between CYP2D6 genotype and tamoxifen metabolites, which is important for future dose titration studies of tamoxifen, the effect of systemic adjuvant treatment on density change in tamoxifen treated patients as well as adherence to adjuvant endocrine treatment, with focus on tamoxifen. There is a need for improved management of side effects to tamoxifen treatment, to optimize quality of life and adherence. Therapeutic drug monitoring of tamoxifen might be an approach. More work on predictive markers and early evaluation of response to tamoxifen is warranted

Hyperon Physics at BESIII

Spin polarization and entanglement are utilized by the BESIII experiment to learn more about the production and decay properties of hyperon-antihyperon pairs in a series of recent analyses of its unprecedented datasets at the $J/\psi$ and $\psi'$ resonances. This has lead to the observation of significant transverse polarisation in decays of $J/\psi$ or $\psi'$ into $\Lambda \bar{\Lambda}$, $\Sigma \bar{\Sigma}$, $\Xi \bar{\Xi}$, and $\Omega \bar{\Omega}$. Because of the non-zero polarization, the decay parameters for the most common hadronic weak decays of both hyperons and antihyperons could be determined independently for the first time. Comparing these to each other yields precise tests of direct, $\Delta S = 1$ CP-violation that complement measurements of kaon decays.Comment: 9 pages, 2 figures, submission to SciPost for inclusion in proceedings of ISMD202

Hypoxic Adaptation and Arsenic Trioxide Treatment in Small Cell Lung Carcinoma

Small cell lung carcinoma (SCLC) is a very aggressive solid tumor and is often widely metastasized by the time of diagnosis. Despite good response to the initial chemotherapy, SCLC cells often develop multidrug resistance to conventionally used chemotherapeutic drugs, which cause almost all SCLC tumors to relapse. The 5-year survival rate for patients with limited disease is around 20% while it is only a few percent for patients with a disseminating disease. Arsenic trioxide (As2O3) is one of the oldest medicines used for treatment of different diseases and it is today used as first-line treatment for patients with relapsed or refractory acute promyelocytic leukemia. Here, we demonstrate that As2O3 is cytotoxic to SCLC cells and xenotransplanted SCLC tumors at clinically relevant concentrations and the effect is also sustained at hypoxic conditions. Areas of low oxygen tensions, hypoxia, are a common characteristic in solid tumors and are associated with aggressive tumor behavior, treatment resistance and poor outcome in several tumor forms. In response to hypoxia, tumor cells induce a transcriptional shift which is mainly regulated by the transcription factors hypoxia-inducible factor (HIF)-1 and HIF-2. HIF proteins consist of two subunits, an oxygen-regulated α-subunit and a constitutively expressed β-subunit. Previous reports have shown that the transcription factors are differentially regulated over time; HIF-1 primarily mediates the acute hypoxic response, whereas HIF-2 dominates during more chronic phases of hypoxia. We found that SCLC tumor specimens and cells lack expression of HIF-2α protein while HIF-1α is expressed at both acute and prolonged hypoxia. In addition, SCLC cells have a high adaptive capacity to hypoxia including a high proliferation rate and low cell death, even though we demonstrated a modest induction of well-known hypoxia-driven genes. We further show that knockdown of HIF1A using siRNA or shRNA, is not significantly affecting the cell viability of cultured SCLC cells at moderate and severe hypoxia or tumor take and tumor growth in SCLC xenografts. We found that SCLC cells are dependent on glutamine metabolism for cell viability and proliferation, in a HIF-independent fashion. The SCLC cells used here are MYC and MYCL amplified and MYC overexpression is known to stimulate glutaminolysis and lipogenesis. In HIF1A repressed cells that overexpress MYC, genes involved in these pathways are further up-regulated at hypoxic conditions. Taken together, our data indicate that the adaptive capacity to hypoxia is partially HIF-independent in MYC amplified SCLC cells

Perceived quality of Swedish with a foreign accent – Comparison of speech with different temporal organization

In an attempt to study variations in perceived quality as an effect of temporally differing Swedish with a foreign accent, recordings of one Spanish and one Estonian speaker were presented to groups of native Swedish listeners. Both inter-speaker differences as well as intraspeaker differences between intact and manipulated versions were studied. Temporal manipulations refer only to the durations of phonologically long segments. Segments were lengthened in the case of the Spanish speaker and shortened in the case of the Estonian speaker. Listeners tended to rate the pronunciation of the Estonian speaker higher than that of the Spanish speaker regardless of intact or manipulated version, whereas listeners who compared intact version to manipulated version tended to rate versions with “long sounds” higher than versions with “short sounds”. A substantial part of the native Swedish listeners rated intact and manipulated versions equally, but if they rated one over the other, the “long sound ” version was always rated as best pronunciation with respect to three quality-related variables

Joint Attention in 12-18 months old children with typical development examined with the Early Social Communication

Joint Attention, or the ability to share attentional focus, is a preverbal communicative behavior which contributes to both the social and the language development. Deficiencies in Joint Attention occur in autism and other clinical groups, which motivate to investigate the ability to detect problems early. In this paper, parts of the international and frequently used assessment The Early Social Communication Scales were used to evaluate Joint Attention in 12-18 months old infants in Sweden. 62 participants were recruited in open preschools, and were divided into three age groups. Correlations between age and Joint Attention were observed. Differences in both initiation and response to Joint Attention were found between the age groups. The older children displayed a higher amount of high level behaviors, which reflects how these behaviors develop over time. No gender differences in Joint Attention were observed. The assessment is considered appropriate for further testing and introduction in Sweden.Joint Attention, eller förmågan till delat uppmärksamhetsfokus, är ett förspråkligt kommunikativt beteende som är kopplat till både den sociala och den språkliga utvecklingen. Brister i Joint Attention förekommer hos personer med autism och inom flera kliniska grupper, vilket motiverar att utreda förmågan för att upptäcka svårigheter tidigt. Ett internationellt och ofta använt instrument för att undersöka förmågan är Early Social Communication Scales. I föreliggande pilotstudie användes delar av instrumentet för att studera Joint Attention hos 12-18 månaders barn i Sverige. 62 deltagare rekryterades på öppna förskolor, och de delades in i tre åldersgrupper. Samband mellan ålder och Joint Attention noterades. Skillnad i frekvens för initiering och respons till Joint Attention noterades mellan åldersgrupperna. De äldre barnen uppvisade fler beteenden på hög nivå, vilket avspeglar hur beteendena utvecklas över tid. Inga könskillnader i användning av Joint Attention noterades. Instrumentet anses lämpligt för vidare utprövning inför en introducering i Sverige

Sustainability Science as a Management Science : Beyond the Natural-Social Divide

In this chapter, we argue that in order to understand the interdisciplinary and transdisciplinary dialectics in sustainability science, it is useful to see sustainability science as a kind of management science, and then to highlight the hard-soft distinction in systems thinking. First, we argue that the commonly made natural-social science dichotomy is relatively unimportant and unhelpful. We then outline the differences between soft and hard systems thinking as a more relevant and helpful distinction, mainly as a difference between perspectives in systemic modeling toward models. We also illustrate that the distinction is methodologically useful to advance sustainability science by enabling us (i) to suggest novel ways of using existing theoretical, experimental, and computational resources of the sciences for renewable resource management, and (ii) to disentangle disciplinary disagreements in climate science.Peer reviewe